George Washington’s smallpox inoculation program was one of his best decisions of the war
Up until modern times, disease, not bullets, bayonets, or cannon fire, had been the great killer of soldiers in all armies. In 1775, smallpox had so devastated the American army in Canada that John Adams bemoaned that “…smallpox is ten times more terrible than the British, Canadians and Indians together.”
Having survived his own bout with smallpox in 1751, Washington was altogether familiar with how disease could rob the cause of a viable army. Not only would smallpox kill off soldiers in the ranks, but the threat of infection also scared away many of the recruits that Washington’s army depended upon.
Starting during the winter of 1777 in Morristown, New Jersey, Washington took the bold and controversial move to have soldiers in his army inoculated against smallpox infection using a technique called variolation. Later during the winter encampment at Valley Forge, Washington went even further, demanding that his entire army be inoculated – an action that required great secrecy since inoculated soldiers were incapacitated for a period of time. By some reports, death by smallpox in the ranks dropped from 17% of all deaths to a low of 1% of all reported deaths – a tremendous reduction.
Historian Elizabeth Fenn, author of Pox Americana: The Great Smallpox Epidemic of 1775-1782, claims that “Washington's unheralded and little-recognized resolution to inoculate the Continental forces must surely rank with the most important decisions of the war…"
https://www.mountvernon.org/george-washington/the-revolutionary-war/ten-facts-about-the-revolutionary-war/