Yellow fever, also called yellow jack or the yellow plague, became one of the most feared diseases throughout the Americas in the nineteenth century. This endemic disease of West Africa traveled to the New World and elsewhere aboard trading ships with their cargoes of slaves. These African blacks, although easily infected, nevertheless withstood the effects so that fewer died from the infection than did Caucasians, American Indians, or Asians. Ironically, as smallpox and measles devastated natives along the Caribbean coast and islands, growing numbers of African slaves were brought to replace those plantation laborers. When the value of Africans over natives became apparent, by virtue of the blacks' resistance to yellow fever, the importation of these Africans increased still further ( 1, 2).
Because it was so lethal for susceptible humans, yellow fever actually disrupted exploration into the Caribbean. In fact, American expansion became possible only after a team led by Walter Reed arrived in Cuba to combat the