Some of the major epidemics in the United States (and elsewhere) are listed below:

Year(s)	Location	Disease	Comments
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
1761	North America & West Indies	Influenza
1772	North America	Measles
1775	North America (especially NorthEast)	unknown
1775-6	Worldwide	Influenza
1783	Dover, DE	Bilious Disorder	"extremely fatal", likely hepatitis
1788	Philadelphia, New York	Measles
1793	Vermont	"putrid fever" and Influenza
1793	Virginia	Influenza	killed 500 in 5 counties in 4 weeks
1793	Philadelphia	Yellow Fever
1793	Harrisburg, PA	Unknown
1793	Middletown, PA	Unknown
1794	Philadephia	Yellow Fever
1796-7	Philadelphia	Yellow Fever
1798	Philadelphia	Yellow Fever	I'd consider this one long 5+ year endemic period with flare-ups
1803	New York	Yellow Fever
1820-3	Nationwide	"Fever"	starts Schuylkill River
1831-2	Nationwide	Cholera	brought from Asia
1832	New York City, and others	Cholera
1833	Columbus, OH	Cholera
1834	New York City	Cholera
1837	Philadelphia	Typhus
1841	Nationwide	Yellow Fever	especially bad in South
1847	New Orleans	Yellow Fever
1847-8	Worldwide	Influenza
1848-9	North America	Cholera
1849	New York	Cholera
1850	Nationwide	Yellow Fever
1850-1	North America	Influenza
1851	Great Plains, IL, MO	Cholera
1852	Nationwide	Yellow Fever	8000 die in New Orleans
1855	Nationwide	Yellow Fever
1857-9	Worldwide	Influenza
1860-1	Pennsylvania	Smallpox
1865-73	Philadelphia, NY, Boston, New Orleans	Smallpox
1865-73	Baltimore, Memphis, Washington DC	Cholera
1873-5	North America, Europe	Influenza
1878	New Orleans	Yellow Fever
1885	Plymouth, PA	Typhoid
1886	Jacksonville, FL	Yellow Fever
1918	Worldwide	Influenza	More people were hospitalized in WW1 from this epidemic than from wounds. Up to 80% death rate in some US Army camps