Yellow fever the introduction of sugar plantations created the conditions for mosquito and viral reproduction, and subsequent outbreaks of yellow fever. Deforestation reduced populations of insectivorous birds and other creatures that fed on mosquitoes and their eggs. Although yellow fever is most prevalent in tropical-like climates, the northern United States were not exempted from the fever. The first outbreak in English-speaking North America occurred in New York City in 1668, and a serious one afflicted Philadelphia in 1793. English colonists in Philadelphia and the French in the Mississippi River Valley recorded major outbreaks in 1669, as well as those occurring later in
1793 Philadelphia yellow fever epidemic was also advocated by Dr. Edward Stevens, who in mid-September claimed it had cured Alexander Hamilton, Secretary of the Treasury, of the fever. Rush searched the medical literature for other approaches. Benjamin Franklin had given him letters sent by Dr. John Mitchell, related to treating patients during a 1741 yellow fever outbreak in Virginia. (Franklin never published the letters.) Mitchell noted that the stomach and intestines filled with blood and that these organs had to be emptied at all costs. "On this account," Mitchell argued, "an ill-timed scrupulousness about the weakness of the body is of bad consequences in these