Located 17 miles south, Camp Cooper was surrendered by the U.S. at the outbreak of the Civil War and used as a Confederate frontier outpost on the defense line from Red River to the Rio Grande. Manned by Texas cavalry, mounted riflemen, and Rangers, it relied on constant patrol and scouting to guard against Indian raids, Union invasion, marauding deserters, and Jayhawkers. Though always short on food supplies, ammunition, and horses, these troops fought the Comanches in numerous engagements while effectively protecting supply trains and pioneer families along the edge of settlement.