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
History of yellow fever The entire Mississippi River Valley from St. Louis south was affected, and tens of thousands fled the stricken cities of New Orleans, Vicksburg, and Memphis. An estimated 120,000 cases of yellow fever resulted in some 20,000 deaths. Memphis suffered several epidemics during the 1870s, culminating in the 1878 epidemic (called the Saffron Scourge of 1878), with more than 5,000 fatalities in the city. Some contemporary accounts said that commercial interests had prevented the rapid reporting of the outbreak of the epidemic, increasing the total number of deaths. People still did not understand how the disease developed or was transmitted, and