The Battle of Fort San Carlos was the westernmost battle of the American Revolution. On May 26, 1780, about 300 townspeople, including Spanish soldiers, French settlers, and enslaved and free African Americans rallied to defend St. Louis. In front of you, along what is now Fourth Street, they had prepared a mile-long trench circling the colonial town.
The town's greatest weapons were the cannons atop the Fort San Carlos tower. The allied British and American Indian forces, traveling from the Upper Midwest, were intent on gaining western territory. Although they were outnumbered two to one, the townspeople stopped the raid, preventing the British from taking control of the Mississippi River.