Smallpox was a serious threat to the success of the Continental Army during the Revolutionary War. The disease had the potential to claim more soldiers than combat. George Washingon, the general of the Continental Army, was very aware of the importance of slowing the spread of smallpox. He quarantined soldiers that showed the earliest signs of the affliction so that they would not inflict others. Washington, who had the disease as a young adult, understood that after contracting the disease, you were immune. After the British left Boston in the midst of an outbreak, he sent his immune troops to defend the city.
During the years of the Revolution, there was a primitive inoculation remedy for smallpox. They would cut the skin of a soldier and infect him with a small amount of the germ from an infected soldiers sores. In this way, the soldier would build up an immunity, but would be sick for several weeks. The illness would render the soldier useless for those weeks. Washington instituted a program that when soldiers enlisted, they would be inoculated. So in addition to receiving your gear, guns, and boots, you would be welcomed with smallpox for a couple of weeks. Sounds like good times.