Fort Gates, originally Camp Gates, was established by Capt. William R. Montgomery on October 26, 1849, as a stockaded United States cantonment on the north bank of the Leon River above Coryell Creek, about five miles east of the site of present Gatesville. The installation was named for Bvt. Maj. Collinson Reed Gates of New York, who won distinction in the battles of Palo Alto and Resaca de la Palma. As the last of a cordon of posts established in 1849 to protect settlers on the frontier from Indians, Fort Gates was authorized by Gen. George Mercer Brooke, commander of the Eighth Military Department. The establishment had eighteen buildings-four for officers' quarters, two for company quarters, three for laundresses, one for muleteers and employees, a hospital, a stable, a forage house, two storehouses, a guardhouse, a bakehouse, and a blacksmith shop. Quarters for a third company were half completed before orders for the building were revoked. Supplies were transported from Washington-on-the-Brazos, Houston, and Indianola. Commanding officers at Fort Gates were Montgomery (1849–50), James G. S. Snelling (1850–51), Carlos Adolphus Waite (1851–52), and Horace Haldeman (1852). The 1850 census enumerated six officers and ninety-four men at the garrison. The personnel included men of companies D, I, F, and H of the Eighth United States Infantry. In April 1851, 256 enlisted men and forty-five officers were stationed at Fort Gates, the most reported in a single month. Lt. George Pickett, later a Confederate general and leader of "Pickett's Charge" at Gettysburg, was stationed at Fort Gates in 1850–51.
Lt. W. H. C. Whiting of the Corps of Engineers, ordered by General Brooke to make a reconnaissance of the cordon of forts, reported early in 1850 that Fort Gates was good only for the protection of its immediate neighborhood, that it needed at least two companies to operate within a radius of sixty or seventy miles, and that the nature of the country was such that the Indians could move in all directions. The district lay in the northern part of Tonkawa country and was visited by the Waco, Comanche, and Lipan Apache Indians. But the Indian menace was soon removed, and the fort was abandoned in March 1852, the first of the line of posts to be evacuated. Though for a time after the removal of the garrison settlers continued to look upon the fort as a refuge from Indian raids, the buildings soon disintegrated until only the rock of the fireplaces remained. Lead Mountain, back of the ruins, was so named because of the number of lead bullets found there. The Cotton Belt railroad had a flag station named Fort Gates near the site of the old post, and a community called Fort Gates prospered there after the construction of Fort Hood in the 1940s.