Letter from Gen. George Washington to John Hancock, President of Congress, regarding an alleged plot of the British to spread smallpox among the American troops, December 4, 1775, signature page

Before closing a lengthy letter to Congress reporting on a variety of topics, Washington passed along information that he had heard from a sailor: that British Gen. William Howe was sending people out from Boston who had been deliberately infected with smallpox so that they might pass on the disease to the Americans surrounding the city. After seeing an increased number of cases in people coming out of Boston, Washington came to believe that smallpox was indeed “a weapon of Defence they Are useing against us.”

National Archives, Records of the Continental and Confederation Congresses and the Constitutional Convention