During the American Revolution, smallpox posed a significant threat to the Continental Army, with the disease responsible for an estimated 90% of deaths among soldiers. Recognizing this danger, George Washington, who had survived smallpox himself during a trip to Barbados in 1751, took decisive action. In January 1777, he ordered a mass inoculation of his troops, starting in Morristown, New Jersey, and Philadelphia, Pennsylvania. This bold move came despite the risks associated with the crude inoculation process of the time, which involved introducing a less virulent strain of the virus through small cuts in the skin. Washington's decision was controversial, as inoculation was not widely accepted and carried the risk of spreading the disease further. However, he believed it was essential to safeguard his army's strength against both the British and the invisible enemy of smallpox.
Washington's inoculation campaign marked the first large-scale, state-funded immunization effort in American history. By February 1777, he informed Congress of his plans, emphasizing the necessity of the measure to prevent the army from being decimated by the disease. The inoculation program proved successful, significantly reducing the impact of smallpox on the Continental Army and allowing them to maintain their fighting capacity. This strategic decision not only demonstrated Washington's leadership but also contributed to the eventual success of the American Revolution. It highlighted the importance of public health measures in military strategy, setting a precedent for future efforts to protect soldiers from disease.