Jonas Salk and the Invention of the Polio Vaccine

The American Revolutionary War

The Revolutionary War, 1775 to 1783, allowed for more wide scale acceptance and use of variolation. George Washington went against the Continental Congress and argued that smallpox posed a threat to military operations and variolation should be mandatory for soldiers.  By 1778, the smallpox death rate among soldiers dropped from 17% to 1%. This was the first instance of mandatory inoculation in the United States.