SOURCES: Sun researcher Paul McCardell contributed to this compilation. Its sources include the Baltimore Health Department; The World Almanac, 1919; The Sun; The Evening Sun; The (Baltimore) Afro-American; The Washington Post; PBS.org; Twoop.com Medical Timelines and the World Health Organization.
Click on the photos in the timeline for larger version.
March 1918: The first wave of the flu infects soldiers at Camp Funston (now Fort Riley) in Kansas.
August 1918: A second, deadly wave arrives in Boston with sailors complaining of cold symptoms.
Sept. 4: First civilian admitted to Boston hospital.
Sept. 8: Flu appears at Camp Devens, 30 miles west of Boston. First deaths in Boston area -- a civilian, a Navy man and a merchant marine. First reports of flu at Philadelphia Naval Yard.
Sept. 22: Henry Scott, 28, of Elkton, dies. The Pennsylvania Railroad lineman and baseball player is the first civilian whose death is blamed on flu in a news report in The Sun.
Sept. 23: Dr. William Henry Welch of Johns Hopkins becomes part of a team sent by the surgeon general to investigate flu at Camp Devens. First cases at Camp Meade in Maryland.
Sept. 24: Boston closes its public schools.
Sept. 26: Baltimore records its first 10 cases.
Sept. 27: "Spanish flu" is nothing more than ordinary "grip," says C. Hampson Jones, a Maryland health official.
Sept. 28: The Fourth Liberty Loan Bond campaign begins, raising money for the Allied troops over the next three weeks. Former President Theodore Roosevelt, whose son Quentin had been killed in action, speaks at Maryland's launch. Philadelphia holds a Liberty Loan parade despite physicians' objections.
Sept. 30: Margaret Baldwin, dubbed "the prettiest woman in Baltimore" by artist James Montgomery Flagg, poses as Goddess of Liberty at a Liberty Loan rally at Lyric Opera House.
Oct. 1: Red Cross volunteers in Baltimore make 18,000 face masks to protect those coming into contact with flu victims. Nationally, more than 14,000 new cases are reported in a 24-hour period.
Oct. 2: City health commissioner John D. Blake bans public dances. Washington, D.C., closes its schools.
Oct. 4: Plans are publicized for the next day's Liberty Loan parade. Eleanor Wilson McAdoo, wife of the Treasury secretary and daughter of President Woodrow Wilson, is set to lead the 25,000 women expected to march.
Oct. 5: Health commissioner Blake abruptly cancels the women's parade. The city lists 117 deaths from the flu during the week ending that day.
Oct. 6: Blake cites drop in new cases in declining to impose bans on theaters and moving picture parlors or to close schools and churches, as some other cities have done. H.J. Moss, director of the Hebrew Hospital, vehemently disagrees, calling for "drastic action." Head lab physician investigating flu at Camp Meade dies.
Oct. 7: Blake closes public schools. The Johns Hopkins University and Loyola College are closed, as are area private schools; 300 motormen are out sick. C&P is down 250 telephone operators as well as one-quarter of its remaining work force. The company asks the public to limit telephone use.
Oct. 9: Morgan College is closed. National Association of Motion Picture Industries votes to suspend filming and releasing pictures for three weeks.
Oct. 10: New infections in the city reach a peak of 1,962 for a single day.
Oct. 11: The Afro-American reports physicians handling as many as 125 flu cases each and "druggists ready to drop." Hospital staffs, already drained by the war, are depleted. Illness reduces personnel at Hebrew Hospital by half.
Oct. 12: Baltimore lists 563 deaths during the week ending that day. Churches and synagogues are closed. So are bowling alleys, pool and billiard halls and Laurel Race track.
Oct. 15: A desperate ad in The Sun offers the then-fabulous sum of $100 a week for a nurse.
Oct. 16: In what will be the city's deadliest day of the pandemic, the flu kills more than 200 people, including the "prettiest woman in Baltimore." Out sick are 186 policemen, 105 firemen and 60 garbage collectors. Plainclothes officers on streetcars are told to arrest anyone disobeying rule against spitting.
Oct. 17: City orders firemen and others to wash the streets to keep down dust and dirt believed to carry germs. Mayor also directs $25,000 to be spent on caskets. Camp Meade offers 500 caskets to the city, which engages laborers to dig graves.
Oct. 18: To relieve overworked undertakers, survivors are asked to wash and dress the bodies of relatives. Elsewhere, the Western Maryland Railway Co. converts Hagerstown Country Club to a hospital.
Oct. 26: Responding to a plea from Baltimore's mayor, 350 soldiers from Camp Meade bury 150 coffins of flu victims that have accumulated on the grounds of Mount Auburn Cemetery, a black cemetery.
Oct. 28: Ban against going to churches and synagogues is lifted. Ban is partially lifted to allow attendance at theaters and moving picture parlors except for matinee performances.
October 1918 becomes the deadliest month in the history of the United States, with 195,000 Americans dying from the flu and complications.
Nov. 1: Blake lifts all remaining bans in Baltimore. Schools reopen two days later.
Nov. 11: Armistice Day celebrated as World War I comes to an end. People around the world celebrate in public places without masks.
Nov. 17: The U.S. Census Bureau reports that flu has killed at least 78,000 in the nation's 46 largest cities, nearly double the lives lost in the American Expeditionary Forces over the course of the entire war. In Baltimore, Commissioner Blake declares that heart disease has overtaken flu and pneumonia as the most common cause of death.
Dec. 10: Flu takes a jump in Baltimore, with 42 new cases and 15 deaths.
Dec. 31: In a third wave, Baltimore records 81 new cases.
It is estimated that 21.5 million people worldwide died in the pandemic.
The World Health Organization lists the death toll from the pandemic as 40 million to 50 million worldwide.