Genealogical research often involves a detailed search for people who disappear from local records, or migrate to parts unknown. This list of american epidemics may help in finding the cause.

1657	Boston	Measles
1687	Boston	Measles
1690	New York	Yellow Fever
1713	Boston	Measles
1729	Boston	Measles
1732-3	Worldwide	Influenza
1738	South Carolina	Smallpox
1739-40	Boston	Measles
1747	CT, NY, PA, SC	Measles
1759	N. America	Measles: areas inhabited by white people
1761	N. America and West Indies	Influenza
1772	N. America	Measles
1775	N. America	Unknown epidemic: especially hard in NE
1775-6	Worldwide	Influenza: one of the worst epidemics
1783	Dover, DE	"Extremely fatal" bilious disorder
1788	Philadelphia and New York	Measles
1793	Vermont	A "putrid" fever and Influenza
1793	Virginia	Influenza: killed 500 in 5 counties in 4 weeks
1793	Philadelphia	Yellow Fever: over 4,000 deaths
1793	Harrisburg, PA	Many unexplained deaths
1793	Middletown, PA	Many unexplained deaths
1794	Philadelphia, PA	Yellow Fever
1796-7	Philadelphia, PA	Yellow Fever
1798	Philadelphia, PA	Yellow Fever: one of the worst
1803	New York	Yellow Fever
1820-3	Nationwide	"Fever" - started Schuylkill River and spread
1822	New York and New Orleans	Yellow Fever
1831-2	Nationwide	Asiatic Cholera: brought by English emigrants
1832	NY City and other major cities	Cholera
1832	New Orleans	Asiatic Cholera: over 1,000 deaths
1832	Ayrshire towns of Stevenston, Dalry and Kilbride	Cholera
1833	Columbus, OH	Cholera
1834	New York City	Cholera
1837	Philadelphia	Typhus
1841	Nationwide	Yellow Fever: especially severe in the south
1847	New Orleans	Yellow Fever
1847-8	Worldwide	Influenza
1848-9	North America	Cholera
1849	New York	Cholera
1849-50	New Orleans	Cholera: 3,000 deaths
1850	Nationwide	Yellow Fever
1850	Alabama, New York	Cholera
1850-1	North America	Influenza
1851	Coles Co., IL, The Great Plains, and Missouri	Cholera
1852	Nationwide	Yellow Fever
1853	New Orleans	Yellow Fever: 8,000 die
1855	Nationwide	Yellow Fever
1857-9	Worldwide	Influenza: one of the greatest epidemics
1860-1	Pennsylvania	Smallpox
1865-73	Philadelphia, NY, Boston, New Orleans, Baltimore, Memphis, Washington DC	Smallpox, a series of recurring epidemics of Cholera, Typhus, Typhoid, Scarlet Fever, Yellow Fever
1873-5	N. America and Europe	Influenza
1878	New Orleans	Yellow Fever: last great epidemic
1878	Memphis, TN	Yellow Fever
1885	Chicago, IL	water-borne disease
1885	Plymouth, PA	Typhoid
1886	Jacksonville, FL	Yellow Fever
1900	Galveston, TX	cholera
1902	Alaska	measles
1905	New Orleans	Yellow Fever: last US outbreak
1918	Worldwide	[high point yr] Influenza: more people were hospitalized in WWI from this epidemic than wounds. US Army training camps became death camps, with 80% death rate in some camps