Epidemics in 19th Century New York City
The population of Manhattan grew from app. 60,000 people in 1800 to app. 2,300,000 people in 1900. (More in Wikipedia)
The statistics for 2008 reveal that app. 1,700,000 people live in Manhattan at present. The population density in Manhattan, in other words, was much higher in the 19th Century than now.
The rapid growth of the city along with the density of the population led to very unhealthy living conditions, particularly among the poor and the immigrants of Five Points. Among many other social reformers, Jacob Riis documented this with his photographs and his text How the Other Half Lives.
Below is a, most likely incomplete, list of epidemics that struck New York City in the 19th Century:
1805: Yellow Fever
1819: Yellow Fever
1822: Yellow Fever
1832: Cholera
1834: Cholera
1847: Typhus
1848-1849: Cholera
1854: Cholera
1862: Typhus
1865-1873: Smallpox
1866: Cholera
1881: Typhus
1882: Typhus
1892: Cholera