Valley Forge is often remembered for its iconic images of weary soldiers and the resolve of George Washington. However, this pivotal winter encampment in 1777–78 was not just a tale of endurance; it was also a groundbreaking moment in public health history. Amidst the harsh conditions, Washington made a daring decision to inoculate his troops against smallpox, a silent but deadly threat that had already taken its toll on the Continental Army.