Fort Chadbourne was a fort established by the United States Army on October 28, 1852, in what is now Coke County, Texas, to protect the western frontier and the Butterfield Overland Mail route. It was manned by the 8th U.S. Infantry. During the early days of the American Civil War, the fort surrendered to the Confederates on February 28, 1861, even before Fort Sumter, South Carolina. The small community of Fort Chadbourne, Texas, is located a few miles to the southwest of the original fort.