Smallpox continued to plague human populations long after Edward Jenner developed the smallpox vaccine in 1796. This was due to both the reluctance of some people to be vaccinated and the difficulty of vaccinating large populations and individuals in remote regions. By the end of the nineteenth century, however, persistent vaccination programs began to eliminate smallpox from some countries. Sweden eradicated smallpox in 1895; Puerto Rico in 1899; Austria and Cuba in the 1920s; Great Britain, the Philippines, and the Soviet Union in the 1930s; and Central America, the Caribbean Islands, and the United States in the 1940s. Finally, in 1967—171 years after Jenner's great discovery—the first serious attempt to eradicate smallpox from the world began.

The Worldwide Eradication Campaign Is Launched

Smallpox had been exterminated from the United States by 1947 when a terrifying event occurred. In March of that year, an American businessman took...