Published in collaboration with California History
Diane M. T. North
The 1918–1920 influenza pandemic remains the deadliest influenza pandemic in recorded history. It began in the midst of World War I (1914–1918), as millions of combatants fought on the battlefields of Europe, Africa, the Middle East, the Far East, and at sea. The exceptionally contagious, unknown strain of influenza virus spread rapidly and attacked all ages. Whereas previous epidemics had affected those under five years of age or the elderly, the new virus especially targeted young adults, ages twenty to forty-four—the age range of sailors, marines, soldiers, pilots, physicians, nurses, and support staff. Influenza spread from person to person by close contact, especially through sneezing, coughing, or sharing items such as drinking cups. Key transmission vectors within the military included training camps, in transit aboard trains or ships, and along the front lines of battlefields. Key transmission vectors for civilians included refugee camps, crowded cities, transportation services, factories, and public gatherings. There were no ventilators, vaccines, antibiotics, or antiviral medicines to help the pandemic’s victims. An estimated 50–100 million people died worldwide, many from complications of pneumonia. Approximately 500 million, or one-third of the world’s population, became infected. More U.S. military personnel died from influenza than from battlefield wounds.
This article examines the evolution of four waves of the 1918–1920 influenza pandemic, emphasizes the role of the U.S. Navy and sea travel as the initial transmitters of the virus in the United States, and focuses on California as a case study in the response to the crisis. Although the world war, limited medical science, and the unknown nature of the virus made it extremely difficult to fight the disease, the responses of national, state, and community leaders to the 1918–1920 influenza pandemic can provide useful lessons in 2020, as the onslaught of the novel coronavirus (or SARS-CoV-2) that causes the disease, COVID-19, forces people worldwide to confront a terrible illness and death.
Problems with 1918–1920 Data
From the outset, it is important to acknowledge several difficulties in understanding the historical complexity of the influenza pandemic: its geographic origin, the precise arrival times as the contagion spread worldwide, and its deadly impact. Scholars continue to debate the geographic origin of the pandemic—the battlefields of western France, the United States, or the Far East. Another challenge is related to charting the path of infection as it reached different populations at different times. The same dilemma exists with the COVID-19 pandemic. After the virus spread from China, U.S. health officials originally thought that the first U.S. COVID-19 death occurred in Washington state on February 26, 2020, but new evidence suggests that the first death occurred in Santa Clara County, California, on February 6, 2020. Dr. Sara Cody, the county’s health officer, recognized that the virus had gone undetected in the United States during January and early February 2020. This news will change as physicians learn more.
More importantly, scholars today warn that the worldwide morbidity and mortality numbers for the 1918–1920 influenza pandemic are understated. In the United States, the available statistics give an incomplete picture of the magnitude of the disease. Between 1918 and 1920, the U.S. population grew slightly, from 103 million to 106.5 million. During that time, an estimated 850,000 people died from influenza and pneumonia. However, out of forty-eight states, only thirty contributed to the 1918 Bureau of Census Mortality Statistics, and only twenty-four states contributed to the 1919 report. In 1920, the bureau was able to count only an estimated 82.3 percent of the U.S. population, including the Territory of Hawaii. In California, with an estimated population of 2.3 to 3.4 million between 1918 and 1920, approximately 29,738 died of influenza and pneumonia during those years, but these data also are unreliable (Table 1).
Not until the last week of September 1918 did the surgeon general of the U.S. Public Health Service (USPHS) designate influenza as a “reportable” disease and request that all public health officials telegraph weekly reports of incidences, even though, by then, the disease had spread to twenty-seven states, including California. Responding to the federal directive, the executive officer of the California State Board of Health (CSBH), Dr. Wilfred H. Kellogg, wrote to all city and county health officers on September 27, 1918, advising that the communicable disease, influenza, now qualified as “reportable and isolatable” under Section 2979 of the Political Code. Kellogg authorized California health officials to “require the isolation of cases appearing in your community, it being hoped in this manner to check the rapid spread of the disease, which otherwise appears inevitable.”
Evolution of the First Wave: The United States and the World, January–July 1918
Scholars now generally accept that the influenza pandemic arrived in the United States in three waves, in spring 1918, autumn–winter 1918, and winter–spring 1919. More recent research identifies a possible fourth wave in the winter and spring of 1920. Some sources suggest that the initial U.S. outbreak appeared at U.S. Army bases in Kansas in March or April of 1918. However, a careful reading of contemporary reports issued by the U.S. Navy and the USPHS provides more precise and generally overlooked information about the infection’s first-wave arrival times in the United States and around the world. Naval records are particularly germane to California, with its 1,200-mile coastline, significant seaports, U.S. Navy and Army installations, and the constant movement of people and goods on ships traveling around the entire Pacific Rim and through the Panama Canal.
The U.S. Navy’s surgeon general described the first “suspicious outbreak of influenza” on board the U.S.S. Minneapolis at the Philadelphia Navy Yard in January, 1918, where twenty-one sailors became ill. By February 1918, as the navy continued to train sailors and marines and protect U.S. merchant ships carrying food and supplies to Europe from German submarine attacks, medical officers recorded approximately 700 influenza cases, including at the navy yards in Portsmouth, NH, Boston, and New York. Of the 700 cases, 350–400 occurred at the U.S. Naval Radio School at Harvard University in Cambridge, Massachusetts. Physicians treating patients at the radio school observed eleven influenza cases with complications due to streptococcus pneumonia. Here, the navy’s description presents another dimension to the disease—the acute role of pneumonia in the 1918–1920 influenza pandemic—and demonstrates the importance of keeping accurate, detailed records during the COVID-19 pandemic due to the complex presence of pneumonia in certain of its sufferers.
The geographic areas affected by influenza expanded in March 1918. The navy reported approximately 300 cases on ships stationed along the U.S. eastern seaboard. By April 1918, as the United States trained and transported more troops, influenza numbers among navy personnel rose to over a thousand, including sailors and marines aboard ships along the southeastern and Gulf coasts and in Cuba, France, and California. In the latter state alone, there were 450 cases (and one death) on the U.S.S. Oregon in the Mare Island Naval Shipyard, 120 cases at the submarine base in San Pedro, and 410 cases at the San Diego Naval Training Camp (for further details, see below).
As military operations intensified, the navy’s 478 influenza cases chronicled in May 1918 show that the disease’s geographic area swelled to ships and shore stations in Ireland, Scotland, England, France, and Gibraltar.
During the summer of 1918, the first wave of the pandemic continued to spread. Many Californians were among those the United States sent to Russia as part of the ill-fated Siberian Expedition. Scholars do not know if they carried the disease with them, contracted it in Siberia as the men mingled with local residents, or both. However, as navy ships traveled across the Pacific in June, the surgeon general recorded first-wave incidences at Pearl Harbor, Hawaii, and Vladivostok, Siberia, in June 1918. In the former, 125 sailors on the U.S.S. Monterey—or 66 percent of the crew—suffered from influenza. In the latter, the disease remained prevalent among the crew of the U.S.S. Brooklyn for eight weeks, with no morbidity or mortality figures given.
By July 1918, the first wave had struck seamen aboard ships at Key West, Florida (U.S.S. Tallahassee, 76 cases), and the Azores (U.S.S. Galatea, 30 cases). Reflecting the escalation of U.S. participation in the war and the changes in war technology, influenza reached military personnel at naval air stations at Wexford and Queenstown, Ireland, and in four French ports. The navy also stated that an influenza pandemic “was evident” in Spain, Austria, Germany, Switzerland, France, and Great Britain.
The First Wave in California: February–June 1918
Although the data lack narrative details, it is important to point out that the USPHS calculated a somewhat elevated or “excess” rate of mortality from influenza and pneumonia in early 1918 in fifty U.S. cities with a population over 100,000, including three in California: San Francisco from February through June; Los Angeles from March through May; and Oakland (located across the bay from San Francisco) from March through April. These were not classified as outbreaks but are noteworthy because the disease was evident.
By April 1918, seven known first-wave influenza outbreaks occurred in separate locations throughout the state. Military physicians attributed three—in San Pedro, San Diego, and Linda Vista—to the arrival of two Japanese training cruisers, the Asama and the Iwate, with a thousand sailors, commanded by Vice Admiral Kantarō Suzuki. The ships docked in San Francisco on March 22 as part of a goodwill tour among allies. During World War I, Japan was allied with the United States, France, and Britain. California military and civilian dignitaries welcomed and socialized with Japanese officials at receptions and dinners. The Japanese cadets toured the Bay Area and attended athletic and cultural events where they mixed with the general public. The cruisers left San Francisco on March 29 and sailed south along the California coast.
The Iwate and Asama docked at Los Angeles harbor on Monday, April 1. On Thursday, April 4, the Chambers of Commerce of San Pedro and Long Beach entertained a hundred officers and midshipmen at a banquet ashore. The next afternoon, Vice Admiral Suzuki welcomed these same officials plus delegates from the mayor’s office, and their wives, to afternoon teas held aboard both cruisers. Four hundred people attended. The Japanese then sailed to San Diego. On April 9, the army training center, Camp Kearny, located in Linda Vista, north of San Diego, held a “Grand Review” in honor of “the Allied Countries.” Admiral Suzuki attended, along with representatives from the French and British militaries.
Following the ships’ visit to Los Angeles, medical officers at the submarine base in San Pedro recorded 120 cases in an outbreak of ten days’ duration that April. The connection was clear to the navy’s surgeon general, who in 1919 reported that the outbreak followed the visit of a Japanese ship “on board which the disease was prevalent.” Soon after the Iwate and Asama departed San Diego, the medical officers at the U.S. Naval Training Camp reported that 410 sailors, or 9 percent of the base complement, were infected with influenza. The origin of this outbreak, too, was obvious to navy doctors: it came “following the visit of a Japanese Squadron.” Pneumonia complicated twelve cases. Camp Kearny’s medical officer—responsible for 560 infected soldiers—also linked the arrival of Japanese ships carrying influenza-infected sailors to his camp’s outbreak.
Four additional first-wave influenza cases, of unknown origin, appeared in California in April 1918—on Mare Island, at Camp Fremont, at Stanford University, and in the state prison at San Quentin. In the April outbreak at the Mare Island Naval Shipyard, located on a peninsula across the Napa River from the town of Vallejo, 450 sailors or “two-thirds of the ship’s company” aboard the battleship U.S.S. Oregon became infected with the influenza virus. One sailor, Harry McKinley Johnson, a musician first class in the U.S. Navy Reserves, died on April 12.
South of San Francisco, U.S. Army medical officers at Camp Fremont, located in Menlo Park, reported another first-wave attack. Camp Fremont hospitalized 1,045 men as officers moved quickly to prevent the spread of the disease. They prohibited indoor assemblies and improved camp sanitation, including disinfecting affected patients’ tents and clothing. The surgeon sprayed the men’s noses and throats with an antiseptic, but these methods proved ineffective. Nineteen men died. In addition, at Stanford University, immediately adjacent to Camp Fremont, administrators counted 260 influenza cases. Patients were isolated and hospitalized, but six died.
North of San Francisco, another first-wave incident occurred in April 1918, in the California state prison at San Quentin. Dr. L. L. Stanley, the resident public health officer at the prison, carefully noted its first influenza infection on April 13. Stanley attributed the arrival of the disease to “the entrance into the institution of a [sick] prisoner who had come from the county jail in Los Angeles, where, he stated, a number of other inmates had been ill.” From April 14 until May 26, Stanley treated “an epidemic of unusual severity” at San Quentin, with 101 patients hospitalized. Seven of these developed bronchopneumonia and three died. He noted that prisoners became ill within two to three days of contact with an infected prisoner. Stanley tracked the course of the disease, which peaked on April 23–24. At least 1,450 people, over 76 percent of the institution’s 1,900 prisoners, reported sick at the height of the outbreak.
The Second Wave in California Naval Stations and Army Camps: August–December 1918
Influenza spread quickly throughout U.S. ships and military installations at home and overseas. Between June 1917 and November 1918, the United States trained nearly two million men and then shipped them overseas. Accompanying those men were at least 15,000 women from the navy, army, American Red Cross (ARC), and private agencies, who served as physicians, nurses, physical and occupational therapists, reconstruction aides, switchboard operators, casualty searchers, and clerks. Late in August 1918, navy doctors observed that a second, more severe wave had evolved: “The type of cases changed; the disease began to spread progressively from one community to another. The percentage of pulmonary complications increased beyond comparison with regard to the earlier epidemics, and influenzal pneumonia frequently began very early in the disease.”
According to the navy’s surgeon general, “in the United States, the first cases of this phase of the pandemic” were recognized on August 27 aboard a ship that housed new recruits at Commonwealth Pier in Boston. The navy transferred those patients to the U.S. Naval Hospital in Chelsea, Massachusetts. Starting with three cases, fifty-eight were ill only two days later, on August 29. The navy reported that “epidemics of like character occurred almost simultaneously in most parts of the world.” As scholars now know, this was the beginning of a second, even more severe wave of the pandemic. According to the scientists David M. Morens and Anthony S. Fauci, the “identit[ies] of viruses during [the] first and third waves are not known.” However, recent research indicates that “at least 2 virus variants [emerged and spread] during the second wave.”
With the onset of the more fatal second wave of influenza in California, 5,188 soldiers became ill and 129 died at Camp Kearny in Linda Vista, near San Diego, from September 24 to December 8, 1918. Unfortunately, officials were slow to respond. Fourteen days after the first case was reported, camp leaders closed all indoor post exchanges (retail operations) and amusement halls. On October 9, they quarantined the camp. New arrivals were detained for five days and examined daily for signs of infection. For ten days—November 2 to 12—authorities ordered everyone in the camp to wear gauze masks. At the 1,280-bed hospital, dishes were boiled, linens were sterilized, and screens were placed between the cots. The camp then established a separate convalescent area for soldiers discharged from the hospital.
The disease also recurred in fall 1918 at the U.S. Naval Training Camp at San Diego, which trained, housed, and fed an average of 4,932 personnel. New infections peaked between September 8 and 30. The final tally was 628 cases with nineteen fatalities for the period from September 21 to December 14.
When the second wave attacked Camp Fremont in Menlo Park, medical officers improved upon their first-wave response in April by quickly closing theaters and post exchanges and canceling YMCA meetings and all assemblies, except for drill formations. Medical staff wore masks, and patients were assigned separate cubicles. Despite these heightened efforts, from October 8 to November 7, doctors treated 2,778 soldiers for influenza and pneumonia; 149 died.
On September 24, 1918, Captain Harry George, the commandant at Mare Island, ordered precautions “in anticipation of an epidemic of influenza”. With 7,657 navy personnel assigned to the yard, Mare Island was unusually permeable to infection. Between 8,000 to 10,000 civilians entered the shipyard daily, most of whom lived in Vallejo and the surrounding towns, typically in overcrowded, unsanitary rooming houses. Additionally, with the nation at war, the navy routinely sent new recruits and draftees to Mare Island to be trained and assigned to ships. Under these circumstances, George believed, an absolute quarantine was unfeasible. He called instead for a modified quarantine and instructed all personnel to take precautions. George ordered new recruits into detention for twenty-one days. Officials redesigned the sailors’ and marines’ sleeping quarters and allocated each man a sleeping area of fifty square feet within the barracks. Curtains hung between the bunks, cots, and hammocks formed cubicles that offered a measure of isolation. George closed on-base theaters (both live performances and “moving pictures”), recreation and reading rooms, classrooms, and churches. The commandant ordered strict isolation for influenza patients. Medical personnel were ordered to wear gowns and face masks, and to disinfect their hands after treating patients. Additional sanitary measures included steam-cleaning clothing and boiling all eating utensils and mess gear in dishwashing machines for at least five minutes.
Despite these efforts, by the end of November 1918, physicians treated 1,536 navy personnel during the second wave. To supplement the permanent, 200-bed Navy hospital, workers at Mare Island constructed thirteen hospital buildings with 550 beds. When this proved inadequate, medical staff set up emergency tents to care for the additional sick during the peak period in October and requested additional nurses and medical officers.
As the second wave overwhelmed navy physicians and corpsmen on Mare Island, civilians in the nearby town of Vallejo turned to the navy for help. In moves that would be familiar during the COVID-19 pandemic, the navy prohibited sailors and marines from leaving the shipyard and urged civic leaders to close their public buildings. To reduce contact between churchgoers, the navy encouraged congregations to hold services out of doors. From November 3 to 30, 1918, Navy corpsmen operated an emergency hospital for civilian employees on the grounds of the navy shipyard, caring for 287 patients. As the crisis worsened and Vallejo city officials were unable to manage, a local order of Dominican nuns temporarily lent the navy its new school building for a hospital, which patients quickly named “St. Vincent’s Navy Hospital.” Beginning on November 2, the nuns served as nurses alongside four navy physicians, twenty-four corpsmen, and fifty-eight support personnel. This hospital also remained open until November 30, ultimately caring for 190 patients.
At San Francisco’s U.S. Naval Training Station, located on Yerba Buena Island, a different story unfolded. On September 23, the commandant imposed an absolute quarantine, recalling all officers, enlisted men, and civilians to base and requiring them to remain on the island. In the barracks, a muslin screen extended around the head and along the side of each man’s cot. The navy implemented what, in 2019–2020, would be called “social distancing”: the station curtailed all contact with San Francisco and Oakland except to collect supplies and welcome recruits and those who “necessarily had to be received.” The navy restricted the actions of tugboat crews and ordered them to stay twenty feet away from people on the dock. Passengers donned gauze face masks before boarding tugboats bound for the island.
Yerba Buena doctors administered then-standard measures designed to prevent contagious disease transmissions. The navy’s surgeon general, for example, reported that anyone arriving from the mainland had his “pharynx and nasal passages thoroughly sprayed with a 10 per cent solution of Silvol,” a solution of silver in water. Parke, Davis & Company, makers of the product, touted it as an antiseptic and germicidal effective in combating infection. Newcomers to Yerba Buena entered a quarantine camp for several days, where they continued to wear masks, received three daily treatments of Silvol spray, and kept a distance of twenty feet from each other. Outside the quarantine camp, everyone on the station had his pharynx and nasal passages sprayed once daily with the same solution. Drinking fountains were “flamed with a gasoline torch, and all telephone transmitters were disinfected twice daily.” The medical staff inoculated everyone on the island with three successive doses of “a mixed bacterial vaccine” on October 12, 15, and 18.
At the time, the navy’s surgeon general recognized that “this was not a pure quarantine experiment.” Yet as long as the quarantine remained in effect, the island remained free of infection. When the station resumed open contact with San Francisco and Oakland on November 21, the pandemic’s second wave battered Yerba Buena. On December 6, sixteen days after the navy lifted the quarantine, the medical officer reported the island’s first influenza case. During December, the navy counted 148 cases of acute bronchitis, thirteen of bronchopneumonia, four of lobar pneumonia, and twenty-five of influenza on Yerba Buena. Three men died of “influenza (influenzal pneumonia)” and two men died of pneumonia. As the photographs illustrate, medical staff gradually obtained the cloth material to keep infected patients isolated from each other on the Drill Hall floor of the Main Barracks.The Second Wave in California Communities: August–December 1918
California newspaper coverage of what would become the most severe influenza wave began haltingly. Only a few California papers reported on the presence of the second wave of influenza in August and September 1918. On August 31, the Sacramento public health officer advised “Sacramento girls” to cover their kisses with a handkerchief to avoid spreading influenza, “which has gained quite a footing in the cities in the East.” On September 25, one news item announced an unknown number of cases on a coast steamer arriving at Los Angeles from San Francisco, twelve cases in Laverne, near Los Angeles, and an unknown number of cases in San Luis Obispo County. However, Dr. Kellogg, the CSBH’s executive officer, did not think these accounts were genuine. He soon learned otherwise. Californians were somewhat oblivious to, and unprepared for, the second wave of a deadly disease.
As explained above, the USPHS did not declare “influenza” as a reportable disease until the last week in September 1918, when it required public health officers nationwide to send in weekly reports by telegram. Immediately after receiving orders from the USPHS, Kellogg contacted all public health officials in the state on September 27 and requested their compliance with official policy. Recognizing the severity of the disease and its threat to public health, Kellogg advised his fellow physicians that “the disease in the present pandemic seems to exhibit an unusual virulence, and is extremely prone to pneumonic complications.” By the time the federal and state notices arrived in local communities, citizens in twenty-seven states, including California, had suffered from the more severe second wave of influenza.
Just as crowded World War I military transports, stations, and camps—and the military’s interaction with local communities—clearly served as breeding grounds for the transmission of influenza, other vectors spread the disease. In California, these included railroad travel, railroad and highway construction camps, and steamship and ferry travel, as individuals moved up and down the coast and around the bays. Dunsmuir, a community near the Oregon border with approximately two thousand residents, was the site of a sizable Southern Pacific Railroad roundhouse used to service and turn its passenger and freight trains. By October 5, Dunsmuir’s first case, reported on September 21, 1918, had multiplied: 109 railroad workers and townspeople were sick.
On October 1, 1918, federal authorities acknowledged the rapid spread of the second wave of influenza throughout the nation. Congress responded by appropriating $1 million ($16 million in 2020 dollars) to enable the USPHS and local boards of health to combat and suppress the influenza pandemic. Congress advised the army, navy, and USPHS to work together to fight the virus. After urging local health authorities to report influenza cases, the surgeon general of the USPHS, Rupert Blue, organized a nationwide campaign warning people of the dangers of the disease, and designated the states’ chief health officers to direct doctors and nurses to serve in areas with high morbidity and mortality.
By October 12, 1918, the USPHS, with the aid of the ARC, had organized a volunteer medical corps. Eighty-eight California communities requested assistance, and 180 California nurses and sixty physicians offered their help. Kellogg clarified “simple isolation” to mean that sick patients should remain in a private room within their homes, and he confirmed that local health officials had the authority to impose a ten-day “detention period.” He ordered doctors, nurses, patients, family members, and those with a cold to wear gauze face masks; and he recommended that barbers, dentists, druggists, and “many others” wear them as a public duty. Newspapers published the CSBH’s instructions for making, cleaning, and disposing of masks, along with guidelines called “What To Do Until the Doctor Comes”. These included staying in bed, keeping warm, and eating nourishing food, such as plain milk, egg and milk, or broth, every four hours. The CSBH reminded people to avoid crowded places and sick people, to walk to work rather than ride public conveyances, to wash hands before eating, and to spend time outdoors in the sunshine. The USPHS distributed over six million pamphlets informing citizens about the perils of the highly contagious virus and circulated posters throughout the country explaining how influenza was transmitted and what precautions to take.
And still Californians kept dying of influenza, with complications from pneumonia. By the end of October, California reported 124,167 cases of influenza and pneumonia, and the number of deaths had climbed to 5,381. These comprised 3,541 males (or 65.8 percent of fatalities) and 1,840 females (34.2 percent). Nearly two-thirds (64.6 percent) of those who died were between the ages of twenty and thirty-nine. The CSBH also noted the racial characteristics of the October deaths: 5,080 were whites (listed as “Caucasians”); 162 Japanese; 57 Negroes (sic); 46 Chinese; and 36 Indians.
California’s two major cities—Los Angeles and San Francisco—responded to the pandemic threat differently. L.A. authorities acted quickly to combat the virus. Their precautions were wise, given the city’s rapidly growing population, which ballooned from 319,198 in 1910 to 576,673 in 1920. Los Angeles counted seven new cases on September 21. Later scholars would identify fifty-five Polytechnic High School students as among the city’s earliest suspected cases. Recognizing the threat to public health, the city’s health commissioner, Dr. Luther Milton Powers, conferred with the mayor, Frederic Thomas Woodman. On October 11, the mayor declared a state of emergency. Taking actions that would be repeated throughout California during March 2020 in the COVID-19 pandemic, the L.A. City Council passed an ordinance closing public gathering places. Citizens who failed to comply could receive a misdemeanor conviction, six months in jail, and a $500 fine ($8,083 in 2020 dollars). The city closed schools, amusement parks, theaters, movie houses, dance halls, concert venues, exhibitions, and religious services. The county health officer ordered schools closed in a dozen nearby communities. City officials canceled two major World War I–era pathways for transmission of the virus: a parade and a Liberty Loan bond fundraiser. Even though Herbert Hoover, head of the U.S. Food Administration, had designated the film industry as “official purveyors” of publicity for his agency, producers and actors agreed to temporarily halt film production, including filming crowd scenes. L.A. officials also organized several hospitals.
Not everyone agreed with the city’s measures. Residents objected to the conversion of Mount Washington Hotel into a convalescent hospital for influenza patients and to the city spending $10,500 ($169,754 in 2020 dollars) to do so. On December 4, the L.A. City Council voted to lift the ban on public gatherings, even though second-wave infection rates confirmed that the contagion continued to spread. By mid-December, a reported 38,382 people were ill.
Community leaders in San Francisco resisted implementing the kinds of draconian measures undertaken in L.A. San Francisco’s population had grown more slowly than that of Los Angeles, with 416,912 residents in 1910 and 506,676 in 1920. Yet the city experienced a higher proportion of influenza morbidity and mortality than its neighbor to the south. The death rates from influenza and pneumonia in the United States overall, in California, and in L.A., San Francisco, and Oakland are summarized in Table 2.
On October 17, 1918, with 21,000 diagnosed influenza cases, a group in San Francisco—including the mayor, James Rolph; city health officer William C. Hassler, MD; and representatives from the USPHS, the ARC, and the military—met to discuss ways to contain the pandemic. The city’s Board of Health closed schools and public amusements, canceled dances and lodge meetings, and prohibited social gatherings. However, it allowed a Liberty Loan bond drive and parade to take place. Officials recommended that church gatherings be held outside. Some city services met outside, such as Police Court. On October 18, Hassler recommended that citizens wear gauze face masks. The following week, despite loud public protest, the city passed an ordinance mandating masks in public or when two or more people were together. ARC volunteers made and distributed 100,000 gauze masks by October 25. The next day, the ARC quickly started converting the Civic Center into a hospital for three hundred influenza patients and appealed for more nurses to care for the sick. Also during October, some San Francisco women learned to drive cars to help physicians and patients; and, just as people in the United States would someday use technology at home for school, work, and socializing during the COVID-19 pandemic, in October 1918 the telephone company installed more phones, a relative novelty, in households with influenza sufferers. By November 2, firemen volunteered to assist the coroner as deaths increased. Due to the generosity of its supporters, the San Francisco chapter of the ARC spent $100,000 ($1.5 million in 2020 dollars) by mid-November to combat influenza in the city and provide relief for the needy.
San Francisco lifted the ban on public gatherings in some parts of the city on November 16. Five days later, officials permitted residents to remove their face masks. On November 25, the city reopened schools, movie houses, theaters, and sports facilities, but the disease continued to spread. According to California Public Health Department data, between October 5, 1918, and January 25, 1919, approximately 39,000 San Franciscans suffered from influenza and pneumonia; 3,600 died. Chart 1 shows the death rates in San Francisco, Los Angeles, Stockton, and Sacramento during the second wave.
In another example of the arrival of the epidemic’s second wave, the public health officer at San Quentin, Dr. Stanley, recorded that the prison’s autumn occurrence followed the October 3, 1918, entrance of a prisoner from Los Angeles whose guard was sick. The prisoner became ill the next day and was hospitalized, but not before exposing others (he had spent the preceding night in a receiving room with ten other men, and ate meals in the dining hall with an estimated 1,900 men).
To safeguard the prisoners’ health, Stanley closed the prison’s indoor “picture show” and invited the Oakland Municipal Band to perform an open-air concert on October 20. Influenza cases peaked the following day. For the next eleven days, Stanley took care of sixty-nine second-wave influenza patients; 8–12 percent of these developed pneumonia, and two died. When Stanley submitted his final report on the outbreak to the USPHS, he concluded: “The most effective means available for combating the spread of the disease in this prison were hospitalization, quarantine, isolation, and the closure of congregating places.” The conclusions reached by the San Quentin doctor are especially important in relation to COVID-19 because the state’s 2020 prison population of approximately 240,000 is difficult to protect.
As scientists and historians now recognize, the influenza epidemic’s second wave struck California during the fall and early winter of 1918 and proved more lethal than the first wave. The new outbreak of infection both caused and revealed a shortage of physicians, nurses, and hospitals. In response, volunteer members of the state’s well-organized Women’s Committee of the Council of Defense shifted from war work to caring for influenza victims. Earlier in the year, the Women’s Committee had established twenty-two Children’s Health Centers statewide. Committee members used information from these centers to identify sick children and their families. Volunteers nursed the sick, obtained beds and bedding, and purchased medicines, fuel, and groceries and delivered them to the ill; they cooked meals for patients and even cleaned their homes. Members of the Women’s Committee set up a motor corps and located drivers to take patients to and from hospitals.
The Third Wave in California: January–May 1919
At the beginning of the new year, Mrs. Bernard T. Miller of Oakland and her six children lay ill with influenza. Her husband, an army captain, was stationed in Virginia. On January 9, 1919, their youngest child, seventeen-month-old Robert, died from the disease. The Oakland Tribune announced “137 New Flu Cases Here in 24 Hours,” with twelve deaths in the same period, including little Robert. Oakland called for more volunteer ARC nurses to care for local cases.
As the third wave of influenza struck, the city of Berkeley, adjacent to Oakland, still debated how to protect its residents. Amid the same kind of arguments that would echo across the United States in 2020 during the COVID-19 pandemic, the Berkeley City Council failed to pass a mask ordinance despite the recommendations of Berkeley’s city health officer, Dr. J. J. Benton, and a University of California physician and professor of hygiene, Dr. Robert T. Legge. The city’s commissioner of public health and safety, Charles D. Heywood, a prominent businessman, opposed the ordinance.
At the beginning of 1919, influenza cases and deaths increased in San Francisco and Los Angeles. In response, Los Angeles, in early January 1919, passed a series of strict quarantine measures, including ordering influenza patients to remain in their homes, and hired quarantine inspectors. By the end of January 1919, the City of Los Angeles had spent all of the funds intended for the entire fiscal year: $247,000 ($3.8 million in 2020 dollars). Later studies reveal that it was money well spent.
In early January 1919, at the onset of the third wave, San Francisco pleaded for more ARC nurses to volunteer at San Francisco Hospital to care for influenza victims, and the mayor even requested help from the navy. On January 19, San Francisco restored its mask ordinance and did not rescind it until February 1. As the third wave continued to expand around the state, the California legislature allocated $55,000 ($840,000 in 2020 dollars) to enable the CSBH to control contagious diseases.
According to the U.S. Census Bureau, a total of 189,326 people died of influenza and pneumonia in 1919. In California, the total number of deaths from influenza and pneumonia for 1919 was 7,240.
The third wave again led to cooperation between military and civilian populations. During the third wave, the naval training station on Yerba Buena reported 127 cases and seventeen deaths. Mare Island recorded 271 cases and nine deaths. Civilians employed at the shipyard again asked the navy for help. In January 1919, the Dominican nuns reopened St. Vincent’s Hospital, where they cared for fifty-five patients, one of whom died. The hospital closed on January 28, shortly after Vallejo lifted the order shuttering public places. It is clear that the second wave proved deadlier than the first and third, but a fourth wave, less deadly than the previous three, struck in 1920, as officials had warned (see Tables 1 and 2).
A Fourth Wave in California: January–March 1920
By the start of 1920, Californians were experienced influenza fighters. In San Francisco, as another wave of the pandemic struck, city officials once again called for ARC nurses to volunteer their services. Long Beach and Los Angeles physicians did not request a ban on public gatherings or close schools, but they did call for preventive isolation.
The U.S. Census Bureau provides evidence of a fourth wave of the pandemic in its analysis of 1920 mortality statistics: “An epidemic of considerable proportions marked the early months of 1920—an epidemic which caused 33 percent as many deaths as the great pandemic of 1918–1919.” In the United States, 182,205 people died from influenza and pneumonia in 1920, including 5,725 Californians.
The 1918–1920 influenza pandemic alarmed everyone—physicians, scientists, public officials, the military, and citizens—with the rapidity of its spread, the severity of its effects, the extraordinary morbidity and mortality counts, and the insidious way that the disease lingered and flared up again. Ship movements during World War I transported influenza from port to port, nation to nation (just as, in 2020, the COVID-19 pandemic swept through aircraft carriers such as the U.S.S. Theodore Roosevelt and among crews and passengers of international cruise ships). One hundred years ago, all efforts to produce a cure, a vaccine, or drugs to alleviate victims’ suffering failed. Although Congress appropriated money for the military and the USPHS, and the latter advertised the dangers of influenza extensively and helped coordinate physicians and nurses, most states and communities devised their own strategies for dealing with the crisis. Some responded more sensibly and effectively than others. Despite the staggering death rate—the most conservative estimate was 850,000 deaths in the United States—no national planning for future emergencies or a national health care plan emerged from the catastrophe.
The influenza pandemic began in the last year of a devastating world war that claimed at least ten million military lives (and twice that many wounded). The pandemic ended as the war’s survivors and refugees struggled to return home and rebuild their lives. It took scientists more than seventy years to recover and reconstruct the 1918 pandemic virus and to begin decoding its genetic characteristics. Scientists continue to learn more about the 1918–1920 influenza pandemic, though many questions remain unanswered.
As the pandemic raged, especially by the onset of what we now know as the second wave, the military pioneered the most effective responses, leading the way in attempts to slow the rate of infection. Wherever possible, military leaders ordered absolute or modified quarantines, enlarged existing hospitals and built new ones, and demanded both better personal hygiene and improved sanitation of facilities. When quarantine orders were lifted too soon, rates of infection escalated. The quick and forthright decisions made by Los Angeles officials, in contrast to those in San Francisco, serve as instructive examples. Also instructive is the cooperation that developed between the U.S. Navy at the Mare Island Naval Shipyard and the Dominican nuns in Vallejo. The spirit of voluntarism displayed by members of the Women’s Committee of the California Council of Defense and the American Red Cross demonstrate how ordinary citizens rose to the challenge of caring for the sick in unprecedented numbers. As the world suffers today with the onslaught of COVID-19, we must look to the lessons of the 1918–1920 influenza pandemic.
 J. K. Taubenberger and D. M. Morens, “1918 Influenza: The Mother of All Pandemics,” Emerging Infectious Diseases 12, no. 1 (2006), http://wwwnc.cdc.gov/eid/article/12/1/05-0979_article.htm#; M. van Wijke et al., “Loose Ends in the Epidemiology of the 1918 Pandemic: Explaining the Extreme Mortality Risk in Young Adults,” American Journal of Epidemiology 187 (2018): 2503–2510. The United States declared war against Germany on April 6, 1917. A more comprehensive article will appear in August 2020: Diane M. T. North, “California and the 1918-1920 Influenza Pandemic,” California History 97, no.3 (Summer 2020).
 Congressional Research Service, American War and Military Operations Casualties: Lists and Statistics, comp. Anne Leland and Mari-Jana Oboroceanu (Washington, DC: Congressional Research Service, 2010), 2. During U.S. involvement in World War I (1917–1918), a total 4,734,991 Americans served. Of the 116,516 total deaths, (including approximately 4,000 Californians), 53,402 were battle deaths and 63,114 deaths were listed as “Other,” mainly from influenza. Carol Byerly, “The U.S. Military and the Influenza Pandemic of 1918–1919,” Public Health Reports 125, Supplement 3 (2010): 83.
 J. A. B. Hammond, W. Rolland, and T. H. G. Shore, “Purulent Bronchitis: A Study of Cases Occurring amongst the British Troops at a Base in France,” Lancet 2 (1917): 41–45; Michael Worobey, Jim Cox, and Douglas Gill, “The Origins of the Great Pandemic,” Evolution, Medicine, and Public Health 2019 (January 21, 2019): 18–25; Mark Osborne Humphries, “Paths of Infection: The First World War and the Origins of the 1918 Influenza Pandemic,” War in History 21 (2014): 55–81.
 New York Times, “Coronavirus Live Updates,” April 22, 2020, 5:30 p.m. ET, https://www.nytimes.com/2020/04/22/us/coronavirus-live-coverage.html?action=click&module=Spotlight&pgtype=Homepage#link-7cf633cc.
 Niall P. A. S. Johnson and Juergen Mueller, “Updating the Accounts: Global Mortality of the 1918–1920 ‘Spanish’ Influenza Pandemic,” Bulletin of the History of Medicine 76 (2002): 105–115..
 U.S. Department of Commerce, Bureau of Census, Mortality Statistics 1918, Nineteenth Annual Report (Washington, DC: Government Printing Office, 1920) (hereafter cited as Mortality Statistics 1918): in the text, on page 27, the census bureau lists 477,467 deaths from influenza and pneumonia (all forms); however, on p. 30 in the unnumbered table, the census bureau lists 367,433 deaths. I selected the higher number for the totals. Bureau of Census, Mortality Statistics 1919, Twentieth Annual Report (Washington, DC: Government Printing Office, 1921) (hereafter cited as Mortality Statistics 1919): in the text, on page 28, the census bureau lists 189,326 deaths from influenza and pneumonia (all forms); however, on the unnumbered table on the same page, the census bureau lists 143,548 deaths. I selected the higher number for the totals. Bureau of Census, Mortality Statistics 1920, Twenty-First Annual Report (Washington, DC: Government Printing Office, 1922) (hereafter cited as Mortality Statistics 1920), 5, for percent of registration area; see 17 and 31 for 62,097 influenza deaths; see 51 for 120,108 pneumonia deaths (all forms) and the combined total of influenza and pneumonia (all forms): 182,205.
 Mortality Statistics 1918, 30: mortality for influenza and pneumonia (all forms), 16,773; Mortality Statistics 1919, 28: mortality for influenza and pneumonia (all forms), 7,240; Mortality Statistics 1920: 5,725 deaths; 314 (influenza: 2,185 deaths); 315 (pneumonia: 3,540 deaths).
 “Epidemic Influenza (‘Spanish Influenza’): Prevalence in the United States,” Public Health Reports 22, no. 29 (September 27, 1918): 1625–1626 (previously reportable diseases in the United States included smallpox, tuberculosis, malaria, measles, mumps, typhoid fever, whooping cough, diphtheria, scarlet fever, poliomyelitis, chickenpox, meningitis, pellagra, and venereal diseases); California State Board of Health and Wilfred H. Kellogg, Influenza: A Study of the Measures Adopted for the Control of the Epidemic, Special Bulletin No. 31 (Sacramento: State Printing Office, 1919) (hereafter cited as Kellogg, Influenza: A Study of Measures), 26. In addition, not until 1930 did the USPHS publish a detailed study of the 1918–1920 excess mortality data. See Selwyn D. Collins, W. H. Frost, Mary Gover, and Edgar Sydenstricker, “Mortality from Influenza and Pneumonia in 50 Large Cities of the United States, 1910–1929,” Public Health Reports 45, no. 39 (September 26, 1930): 2277–2363.
 Howard Markel, Alexandra M. Stern, J. Alexander Navarro, and Joseph R. Michalsen, “A Historical Assessment of Nonpharmaceutical Disease Containment Strategies Employed by Selected U.S. Communities during the Second Wave of the 1918–1920 Influenza Pandemic” (Fort Belvoir, VA: Defense Threat Reduction Agency, January 31, 2006), 27–32; Johnson and Mueller, “Updating the Accounts: Global Mortality of the 1918–1920 ‘Spanish’ Influenza Pandemic,” 107; Nancy K. Bristow, American Pandemic: The Lost Worlds of the 1918 Influenza Epidemic (Oxford: Oxford University Press, 2012), 3; Alfred W. Crosby, America’s Forgotten Pandemic: The Influenza of 1918 (Cambridge: Cambridge University Press, 1989), 203–204.
 For the March cases at Camp Funston, Fort Riley, Kansas, see “1918 Influenza Pandemic Historic Timeline,” Centers for Disease Control and Prevention, U.S. Department of Health and Human Services (page last reviewed March 20, 2018), https://www.cdc.gov/flu/pandemic-resources/1918-commemoration/pandemic-timeline-1918.htm (accessed March 26, 2020); Crosby, America’s Forgotten Pandemic, 18. For April 5, 1918, cases in Haskell, Kansas, see “1918 Influenza Pandemic Historic Timeline,” Centers for Disease Control and Prevention, U.S. Department of Health and Human Services (page last reviewed March 20, 2018); https://www.cdc.gov/flu/pandemic-resources/1918-commemoration/pandemic-timeline-1918.htm (accessed March 26, 2020). For March and April 1918, see Carol R. Byerly, Fever of War: The Influenza Epidemic in the U.S. Army during World War I (New York: New York University Press, 2005), 71. The army also reported influenza cases in March 1918 at training camps in New York, New Jersey, Maryland, and Oklahoma, but that information has been overlooked because of the emphasis on Kansas. U.S. Army, Annual Report of the Surgeon General, U.S. Army 1919, 2 vols. (Washington, DC: Government Printing Office, 1919), vol. 1, 784 (hereafter cited as Annual Report of the Surgeon General, U.S. Army 1919).
 U.S. Navy Department, Bureau of Medicine and Surgery, Annual Report of the Surgeon General, U.S. Navy 1919 (Washington, DC: Government Printing Office, 1919), 367 (hereafter cited as Annual Report of the Surgeon General, U.S. Navy 1919); U.S. Department of Navy, Naval Historical Center, “Casualties: U.S. Navy and Marine Corps Personnel Killed and Injured in Selected Accidents and Other Incidents Not Directly the Result of Enemy Action,” https://www.ibiblio.org/hyperwar/NHC/accidents.htm (accessed March 18, 2020).
 Annual Report of the Surgeon General, U.S. Navy 1919, 367.
 Richard Levitan, “The Infection That’s Silently Killing Coronavirus Patients,” New York Times, April 20, 2020, https://www.nytimes.com/2020/04/20/opinion/coronavirus-testing-pneumonia.html; John F. Brundage and G. Dennis Shanks, “Deaths from Bacterial Pneumonia during the 1918–1919 Influenza Pandemic, Emerging Infectious Diseases 14 (August 2008): 1193–1199.
 Annual Report of the Surgeon General, U.S. Navy 1919, 367–368.
 Ibid., 368.
 Ibid, 368.
 Ibid., 368.
 Ibid., 370.
 Collins et al., “Mortality from Influenza and Pneumonia in 50 Large Cities of the United States, 1910–1929,” table A: “Excess Monthly Death Rates (annual basis) per 100,000 from Influenza and Pneumonia in Each of 50 Cities in the United States, 1910–1929”: Los Angeles, 2310; San Francisco, 2317; Oakland, 2313.
 San Francisco Examiner, “2 Japanese Training Ships Pay a Visit,” March 23, 1918, 6; San Francisco Examiner, “Japanese Training Ships Visit Port,” March 24, 1918, 3; San Francisco Examiner, “Consul to Entertain Japanese Officers,” March 25, 1918, 2; San Francisco Examiner, “S.F. Japanese Hold Big Field Day Show,” March 25, 1918, 8; Oakland Tribune, “Honor Japanese,” March 28, 1918, 4; San Francisco Examiner, “Japanese Admiral Tells Nippon Aims,” March 29, 4; Eric Lacroix and Linton Wells II, Japanese Cruisers of the Pacific War (Annapolis, MD: Naval Institute Press, 1997), 552, 657–658.
 Long Beach Daily Telegram, “Jap Training Ships in L. A. Harbor,” April 2, 1918, 9; Long Beach Press, “Japanese Guests Feted by Local Organizations,” April 5, 1918, 2; Long Beach Daily Telegram, “Jap Officers Return Courtesies,” April 6, 1918, 16.
 History of the Fortieth (Sunshine) Division, 1917–1919 (Los Angeles, CA: C.S. Hutson, 1920), 65; Bakersfield Morning Echo, “Kearny Division Men Reviewed by Allied Officers,” April 10, 1918, 10.
Annual Report of the Surgeon General, U.S. Navy 1919, 368.
 Annual Report of the Surgeon General, U.S. Navy 1919, 368.
 U.S. Army, Medical Department, Office of Medical History, and Maj. Milton W. Hall, “Inflammatory Diseases of the Respiratory Tract,” in The Medical Department of the United States Army in the World War, vol. 9: Communicable and Other Diseases (Washington, DC: Government Printing Office, 1928), 133 (hereafter cited as Communicable and Other Diseases).
Annual Report of the Surgeon General, U.S. Navy 1919, 367–368 (The medical officer did not list a possible source for the disease.); “Died of Accident or Other Causes, Including Camp Deaths,” Yolo in Word & Picture (Woodland, CA: Woodland Daily Democrat, 1920), 10; “Harry McKinley Johnson,” Find a Grave, https://www.findagrave.com/memorial/125036704/harry-mckinley-johnson (accessed March 25, 2020). See also Diane M. T. North, California at War: The State and the People during World War I (Lawrence: University Press of Kansas, 2018), 29–66, 109–177.
 Annual Report of the Surgeon General, U.S. Army 1919, vol. 1, 784.
 Kate Chesley, “100 Years Ago, the Spanish Flu Hit the Stanford Campus,” Stanford News, March 14, 2018, https://news.stanford.edu/thedish/2018/03/15/100-years-ago-the-spanish-flu-hit-the-stanford-campus/.
 L. L. Stanley, “Influenza at San Quentin Prison, California,” Public Health Reports 34, no. 19 (May 9, 1919): 996.
 Ibid., 996–997.
 Frank M. McMurry, The Geography of the Great War (New York: Macmillan, 1919), 31; North, California at War: The State and the People during World War I, 43–46, 81–105.
 Annual Report of the Surgeon General, U.S. Navy 1919, 370. See also David M. Morens, Jeffery K. Taubenberger, and Anthony S. Fauci, “Predominant Role of Bacterial Pneumonia as a Cause of Death in Pandemic Influenza: Implications for Pandemic Influenza Preparedness,” Journal of Infectious Diseases 198 (October 1, 2008): 962–970.
 Annual Report of the Surgeon General, U.S. Navy 1919, 370.
 Ibid., 371.
 Ibid., 370.
 Morens and Fauci, “The 1918 Influenza Pandemic: Insights for the 21st Century,” 1019.
 Annual Report of the Surgeon General, U.S. Army 1919, vol. 1, 746, 634 (table 304); Communicable and Other Diseases, 138.
 Annual Report of the Surgeon General, U.S. Navy 1919, 372, 374 (table 1), 375, (table 3), 376 (table 4). The medical officer speculated that the intense nature of the disease in the spring modified its course in the autumn.
 Communicable and Other Diseases, 138.
 Annual Report of the Surgeon General, U.S. Navy 1919, 429; see 445–446 for “Commandant’s Order No. 386, Mare Island, Cal., September 24, 1918.”
 Capt. Thomas L. Snyder, MC, USNR, “The Great Flu Crisis at Mare Island Navy Yard, and Vallejo, California,” Navy Medicine 94, no. 5 (September–October 2003), 26.
 Annual Report of the Surgeon General, U.S. Navy 1919, 445.
 Ibid., 445–446.
 Snyder, “The Great Flu Crisis at Mare Island Navy Yard, and Vallejo, California,” 26; Annual Report of the Surgeon General, U.S. Navy 1919, 35.
 Snyder, “The Great Flu Crisis at Mare Island Navy Yard, and Vallejo, California, ”27–28; San Francisco Examiner, “Vallejo Asks Navy Aid with 1,000 Flu Cases,” October 31, 1918, 13; “Receipts of the Secretary General’s Office,” Catholic Education Association Bulletin 16 (November 1919), 26, mentions the Dominican sisters in Vallejo.
 Annual Report of the Surgeon General, U.S. Navy 1919, 428.
 “Silvol—A Useful Germicide,” Texas Medical Journal 33 (January 1918): 335.
 Annual Report of the Surgeon General, U.S. Navy 1919, 428.
 Annual Report of the Surgeon General, U.S. Navy 1919, 429. The “first wave” of the pandemic appears to have missed Yerba Buena.
 The Sacramento story was reported in the Santa Barbara Daily News and Independent, “If You Must, Use a Kerchief,” August 31, 1918, 2.
 Sacramento Bee, “Spanish Influenza Spreading in South,” September 25, 1918, 5. Because Spain witnessed well-published high morbidity and mortality cases during the first wave of 1918, the disease earned the popular name “Spanish Influenza” or “Spanish Flu.”
 “Epidemic Influenza (‘Spanish Influenza’): Prevalence in the United States,” Public Health Reports 22, no. 29 (September 27, 1918): 1625–1626; Kellogg, Influenza: A Study of Measures, 26.
 “Epidemic Influenza (‘Spanish Influenza’): Prevalence in the United States,” 1625–1626, 1644.
 California State Board of Health, Monthly Bulletin 14, no. 7 (January 1919): 226; Jessica Skropanic, “Bon Voyage: Make Tracks to California Train Stations, Part Three,” Record Searchlight, June 19, 2014, http://archive.redding.com/lifestyle/bon-voyage-make-tracks-to-california-train-stations-part-three-ep-375171960-354445101.html; Richard J. Orsi, “Railroads and the Urban Environment: Sacramento’s Story,” in Christopher J. Castaneda and Lee M. A. Simpson (eds.), River City and Valley Life: An Environmental History of the Sacramento Region (Pittsburgh: University of Pittsburgh Press, 2013), 89–90.
 Public Resolution, No. 42, U.S. Statutes at Large 40, Ch. 179 (October 1, 1918): 1008; U.S. Department of Labor, Bureau of Labor Statistics, “CPI Inflation Calculator,” http://www.bls.gov/data/inflation_calculator.htm (accessed May 1, 2020; hereafter cited as “CPI Inflation Calculator”).
 Gary Gernhart, “A Forgotten Enemy: PHS’s Fight against the 1918 Influenza Pandemic,” Public Health Chronicles 114 (November–December 1999): 559–560, https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1308540/pdf/pubhealthrep00024-0077.pdf.
 California State Board of Health, Monthly Bulletin 14, no. 7 (January 1919): 221, 226; Kellogg, Influenza: A Study of Measures, 16–18, 26; San Francisco Examiner, “State Doctors Are Mobilized,” October 11, 1918, 4; Sacramento Bee, “Everyone with a Cold Must Wear a Mask,” October 22, 1918, 1.
 Gernhart, “A Forgotten Enemy: PHS’s Fight against the 1918 Influenza Pandemic,” 560.
 California State Board of Health, Monthly Bulletin 14, nos. 5 and 6 (November–December 1918): for October morbidity, see 173; for September and October mortality and other data, 189.
 U.S. Department of Commerce, Bureau of Census, Thirteenth Census 1910, vol. 2: Population (Washington, DC: Government Printing Office, 1913), 157; and Fourteenth Census 1920, vol. 1: Population, detailed tables (Washington, DC: Government Printing Office, 1921), 95–96 (table 49); 151 (table 50); 183–185 (table 51).
 “Epidemic Influenza: Prevalence in the United States,” 1688. The USPHS noted seven influenza cases in the city of Los Angeles by September 21.
 “Los Angeles, California,” in The American Influenza Epidemic of 1918–1919, A Digital Encyclopedia, ed. J. Alex Navarro and Howard Markel (Ann Arbor: University of Michigan Center for the History of Medicine and Michigan Publishing, University of Michigan Library, 2016) (hereafter cited as “Los Angeles, California”), https://quod.lib.umich.edu/f/flu/cities/city-losangeles.html (accessed March 30, 2020).
 Ibid; “CPI Inflation Calculator.”
 “Los Angeles, California”; North, California at War: The State and the People during World War I, 169.
 Ibid.; “CPI Inflation Calculator.”
 “Los Angeles, California.”
 Thirteenth Census 1910, vol. 2: Population, 157; Fourteenth Census 1920, vol. 1: Population, detailed tables, 95–96 (table 49); 151 (table 50); 183–185 (table 51); Mortality Statistics 1920, 29–30.
 W. H. Frost, “The Epidemiology of Influenza, 1919, with a commentary by Thomas M. Daniel, Public Health Reports 121, Supplement 1 (2006): 148–159 (Frost’s study was first published in 1919); “San Francisco, California,” in The American Influenza Epidemic of 1918–1919: A Digital Encyclopedia (herefter cited as “San Francisco, California”), https://quod.lib.umich.edu/f/flu/cities/city-sanfrancisco.html (accessed March 28, 2020).
 San Francisco Chronicle, “Red Cross Gives Out 100,000 Gauze Masks,” October 25, 1918, 7.
 San Francisco Chronicle, “Red Cross Rushes Quarters at Civic Center for Use as Hospital to Fight Influenza,” October 26, 1918, 1.
 San Francisco Examiner, “Women Drive Cars to Aid Doctors,” October 25, 1918, 7; San Francisco Chronicle, “Phones Added for Influenza Sufferers,” October 23, 1918, 1.
 San Francisco Chronicle, “Firemen Volunteer to Assist Coroner,” November 2, 1918, 1.
 San Francisco Examiner, “$100,000 Spent to Fight ‘Flu,’ ” November 21, 1918, 11; “CPI Inflation Calculator.”
 “San Francisco, California,” 91–120.
 Arseny K. Hrenoff, “The Influenza Epidemic of 1918–1919 in San Francisco,” Military Surgeon 89 (November 1941): 807, table 1A: 2,257 died from October through December 1918 and 1,379 died in the first two months of 1919.
 Kellogg, Influenza: A Study of Measures, 5.
 Stanley, “Influenza at San Quentin Prison, California,” 999–1001.
 Ibid., 1007.
 California State Council of Defense, Report, Women’s Committee of the State Council of Defense of California from June 1, 1917 to January 1, 1919 (Los Angeles, 1919), 36.
 Oakland Tribune, “Flu Takes Baby as Six Others Improve,” January 10, 1919, 3.
 Oakland Tribune, “137 New Flu Cases Here in 24 Hours,” January 10, 1919, 3.
 Oakland Tribune, “Single Vote Able to Kill Masking Law,” January 10, 1919, 3.
 “Los Angeles, California.”
 Ibid.; “CPI Inflation Calculator.”
 Howard Markel, Harvey B. Lipman, J. A. Navarro, Alexandra Sloan, Joseph R. Michalsen, Alexandra M. Stern, and Martin S. Cetron, “Nonpharmaceutical Interventions Implemented by US Cities during the 1918–1919 Influenza Pandemic,” Journal of the American Medical Association 298 (August 8, 2007): 644–654.
 San Francisco Examiner, “Need of Nurses at S. F. Hospital Declared Vital,” January 3, 1919, 5; San Francisco Examiner, “Rolph Calls for Navy Nurses,” January 4, 1919, 5.
 “San Francisco, California,” 91–120.
 California, The Statutes of California and Amendments to the Codes, 43rd session, 1919 (Sacramento: State Printing Office, 1919), 838: Chapter 449, May 22, 1919; “CPI Inflation Calculator.”
Mortality Statistics 1919, 28. The government’s data for separate influenza and pneumonia numbers for the entire United States contain inconsistencies in the tables in relation to the overall number of mortalities explained in the text. For California cities, by type of disease, see 200 for influenza and 201 for pneumonia (Los Angeles: 637 influenza deaths and 418 pneumonia deaths; Oakland: 234 influenza deaths and 273 pneumonia deaths; San Francisco: 763 influenza deaths and 659 pneumonia deaths).
 U.S. Navy, Bureau of Medicine and Surgery, Annual Report of the Surgeon General, U.S. Navy 1920 (Washington, DC: Government Printing Office, 1920), 206 (hereafter cited as Annual Report of the Surgeon General, U.S. Navy 1920), 206.
 Snyder, “The Great Flu Crisis at Mare Island Navy Yard, and Vallejo, California,” 28.
 San Francisco Examiner, “City to Join State Board in ‘Flu’ War,” January 30, 1920, 3.
 Long Beach Press, “Influenza as Epidemic to Be Met by Isolation,” January 27, 1920, 9; Long Beach Press, “Same Measures in Los Angeles as Long Beach,” January 27, 1920, 9.
 Mortality Statistics 1920: percent: 5; quote: 29–30; total: 31; influenza: 31 (62,097 deaths); pneumonia: 51 (120,108 deaths); Californians, total: 314–315; influenza: 314 (2,185 deaths); pneumonia: 315 (3,540 deaths).
 Gordon Lubold and Nancy C. Youssef, “U.S.S. Theodore Roosevelt Outbreak Is Linked to Flight Crews, Not Vietnam Visit,” Wall Street Journal, April 15, 2020, https://www.wsj.com/articles/uss-theodore-roosevelt-outbreak-is-linked-to-flight-crews-not-vietnam-visit-11586981891; Centers for Disease Control and Prevention, U.S. Department of Health and Human Services, “Public Health Responses to COVID-19 Outbreaks on Cruise Ships—Worldwide, February-March 2020,” March 27, 2020, at https://www.cdc.gov/mmwr/volumes/69/wr/mm6912e3.htm.
 Antoine Prost, “The Dead,” in Jay Winter (ed.), The Cambridge History of the First World War, vol. 3: Civil Society (Cambridge: Cambridge University Press, 2014), 587–591. The exact numbers for civilian casualties are unknown; conservative estimates suggest ten million.
 Douglas Jordan, Terrence Tumpey, and Barbara Jester, “The Deadliest Flu: The Complete Story of the Discovery and Reconstruction of the 1918 Pandemic Virus,” Centers for Disease Control and Prevention, U.S. Department of Health and Human Services (page last reviewed Dec. 17, 2019), https://www.cdc.gov/flu/pandemic-resources/reconstruction-1918-virus.html (accessed March 18, 2020); Jeffrey K. Taubenberger, Ann H. Reid, Karen E. Bijwaard, and Thomas G. Fanning, “Initial Genetic Characterization of the 1918 ‘Spanish’ Influenza Virus,” Science 275 (March 21, 1997): 1793–1796; Jeffrey K. Taubenberger, David Baltimore, Peter C. Doherty, Howard Markel, David M. Morens, Robert G. Webster, and Ian A. Wilson, “Reconstruction of the 1918 Influenza Virus: Unexpected Rewards from the Past,” mBio 3, no. 5 (September–October 2012): 1–5, https://mbio.asm.org/content/mbio/3/5/e00201-12.full.pdf; John S. Oxford and Douglas Gill, “Unanswered Questions about the 1918 Influenza Pandemic: Origin, Pathology, and the Virus Itself,” Lancet Infectious Diseases 8, no. 11 (published online, June 20, 2018), https://www.thelancet.com/pdfs/journals/laninf/PIIS1473-3099(18)30359-1.pdf.
Diane M. T. North is an award-winning professor of history at the University of Maryland Global Campus and the author of California at War: The State and the People during World War I (University Press of Kansas, 2018).
Copyright: © 2020 Diane M.T. North. This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International License (CC-BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. See http://creativecommons.org/licenses/by/4.0/