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 atmosphere that might last 50 years and make deadly epidemics almost certain. Yellow fever epidemics became seen as a national crisis. When in 1855 a French doctor published an 813-page history of yellow fever in Philadelphia, covering outbreaks from 1699 to 1854, he devoted only a few pages to the 1793 epidemic. General 20th-century US histories, such as the 10-volume "Great Epochs in American History," published in 1912, used short excerpts from Carey's account. The first history of the epidemic to draw on more primary sources was J. H. Powell's "Bring Out Your Dead" (1949), but he did not use