Globalization and disease Spanish soldiers introduced smallpox by contact with natives of the Aztec capital Tenochtitlan. A devastating epidemic broke out among the indigenous people, killing thousands. In 1617, smallpox reached Massachusetts, probably brought by earlier explorers to Nova Scotia, Canada.” By 1638 the disease had broken out among people in Boston, Massachusetts. In 1721 people fled the city after an outbreak, but the residents spread the disease to others throughout the thirteen colonies. Smallpox broke out in six separate epidemics in the United States through 1968. The smallpox vaccine was developed in 1798 by Edward Jenner. By 1979 the disease had been
Mexican–American War campaigns May, and, on August 1, 1848, the last American soldier departed for home. All the casualties among American soldiers in the Mexican–American War amounted to 1,192 killed in action, 529 died of wounds, 362 suffered accidental death and 11,155 soldiers died from disease. Disease claimed a toll seven times greater than that of Mexican weapons. Yellow fever epidemics, "La Vomito", exacted a terrible toll. In addition, diarrhea, dysentery and typhoid claimed lives amid the poor sanitation common to the army camps of this period. The casualties caused by disease in the Mexican Army have never been estimated but were probably