1793 Philadelphia yellow fever epidemic

During the 1793 yellow fever epidemic in Philadelphia, 5,000 or more people were listed in the register of deaths between August 1 and November 9. The vast majority of them died of yellow fever, making the epidemic in the city of 50,000 people one of the most severe in United States history. By the end of September, 20,000 people had fled the city, including congressional and executive officials of the federal government. Most did not return until after the epidemic had abated in late November. The mortality rate peaked in October before frost finally killed the mosquitoes and brought an end to the outbreak. Doctors tried a variety of treatments but knew neither the origin of the fever nor that the disease was transmitted by mosquitoes (this information was not verified until the late 19th century).

The mayor and a committee of two dozen organized a fever hospital at Bush Hill and other crisis measures. The assistance of the Free African Society was requested by the city and readily agreed to by its members. Parties mistakenly assumed that people of African descent would have the same partial immunity to the new disease as many had to malaria, which was typically the most common source of fever epidemics during the summer months.^[2] Black nurses aided the sick, and the group's leaders hired additional men to take away corpses, which most people would not touch. But black people in the city died at the same rate as whites, about 240 altogether.

Some neighboring towns refused to let refugees in from Philadelphia, fearing that they were carrying the fever. Major port cities, including those in Baltimore and New York City had quarantines against refugees and goods from Philadelphia, although New York City sent financial aid to Philadelphia.