1869 | September 23—Mary Mallon is born in Cookstown, County Tyrone, Ireland. |
1870–1910 | More than 20 million immigrants come to the United States. |
1870 | February 3—George A. Soper is born in Brooklyn, New York. |
1873 | November 15—S. Josephine Baker is born in Poughkeepsie, New York. |
1880 | Karl Eberth identifies the typhoid bacterium. |
1883 | Mallon immigrates to America. |
1896 | Georges Widal develops a test for typhoid fever. |
1898 | Spanish-American War. |
1900 | September—TYPHOID: Mamaroneck, New York, family; 1 victim. |
| September 8—A deadly hurricane strikes Galveston, Texas; Soper helps with cleanup. |
1901 | December—TYPHOID: New York City family; 1 victim. |
1902 | June—TYPHOID: Drayton family, Dark Harbor, Maine; 9 victims. |
| November—Robert Koch announces the discovery of healthy typhoid fever carriers. |
1903 | January—TYPHOID: Epidemic begins in Ithaca, New York; the city water supply is blamed. |
| March–August—Soper helps control the Ithaca epidemic. |
1904 | June—TYPHOID: Gilsey family, Sands Point, New York; 4 victims. |
1906 | August–September—TYPHOID: Warren family, Oyster Bay, New York; 6 victims. |
| October—TYPHOID: Kessler family, Tuxedo Park, New York; 1 victim. |
| Fall—Soper is hired to investigate the Oyster Bay outbreak and begins his search for Mallon. |
1907 | February—TYPHOID: Bowne family, New York City; 2 victims, including 1 death. |
| March—Soper tells New York City Department of Health about Mallon. She is captured and detained. |
1908 | Summer—Baker becomes director of the Division of Child Hygiene. |
| September—The nickname “typhoid Mary” first appears in print, in the Journal of the American Medical Association. |
June 20—Popular press first uses nickname “Typhoid Mary,” in the New York American. |
1909 | June 28—Mallon’s lawyer files a petition for her release in New York State Supreme Court. |
| June 29—Mallon appears in court. |
| July 16—Court orders Mallon returned to North Brother Island. |
1910 | February—Mallon is released by the health commissioner. |
1911 | U.S. Army requires all soldiers to receive the typhoid vaccine. |
| December—Mallon files a lawsuit against New York City. |
1914 | July—World War I breaks out. |
| October—Mallon is hired as a cook at Sloane Hospital for Women in New York City. |
1915 | January–February—TYPHOID: Sloane Hospital for Women; 25 victims, including 2 deaths. |
| March 26—Mallon is arrested and taken back to North Brother Island. |
1917–18 | United States fights in World War I until its end. |
1918 | Mallon is hired as a helper at Riverside Hospital and allowed day trips off North Brother Island. |
1923 | Soper becomes managing director of the American Society for the Control of Cancer. Baker retires from the Department of Health and begins a speaking and consulting career. |
1932 | December—Mallon suffers a debilitating stroke. |
1938 | November 11—Mary Mallon dies on North Brother Island. Veterans (Armistice) Day is observed for the first time in the United States. |
1945 | February 22—S. Josephine Baker dies in New York City. |
1948 | Scientists discover an antibiotic to treat typhoid fever. |
| June 17—George Soper dies on Long Island, New York. |
1963 | North Brother Island is abandoned. |