By the 1790s, Philadelphia was a thriving port city that saw numerous ships arriving daily from foreign ports throughout the Atlantic world. In 1793, many of these in-bound ships were not carrying the typical goods to be sold in the local market, but were instead carrying displaced Saint Domingans fleeing the bloody turmoil of the Haitian Revolution. Their arrival set off one of the biggest outbreaks of yellow fever Philadelphia had seen in over three decades. What resulted from this outbreak was a high number of victims and a fearful public demanding answers from their medical community. This paper takes an in-depth look at the state of Philadelphia just prior to the outbreak, the arguments of the nature of fever coming from prominent members of the medical community while they struggled to treat their patients, and the attempts made to slow the transmission of yellow fever both during and after the 1793 epidemic. The urban infrastructure of Philadelphia and quality of the city’s atmosphere were now being considered as potential contributors to the transmission of yellow fever throughout the city. These considerations changed how Philadelphia physicians understood the nature of yellow fever, as well as their recommendations to prevent its return in future years.