The last previous outbreak among the Blackfoot had been in 1781, so by 1837 most of the population was susceptible. The contemporary descriptions leave some possibility open that it could have been some other disease, but yellow fever seems the most likely. 1743-1745 Yellow fever struck New York again. A correlation with the dockyard areas was noticed, but mosquitoes were still not recognized as the vector. A widespread epidemic of influenza hit New England, New York and Nova Scotia in fall 1789.
Most deaths appear to have been from secondary pneumonia.
The fourth cholera pandemic of the 19th century began in India in 1863, spread first to the middle east, and then into the Mediterranean. It arrived in New York on a ship coming from France in October 1865, and spread rapidly. Public health reform kept the death toll lower than in previous epidemics, but there were tens of thousands of deaths nonetheless. Another wave swept through the south and midwest in 1873, hitting particularly hard in the Mississippi and Ohio valleys. The New York City Board of Health recommended that all residents be vaccinated in 1870, but there was widespread public resistance, since the vaccine itself was not without risk, and people perceived the campaign as creating a panic situation and allowing doctors to profit from it.