Fort Lincoln. When the war with Mexico ended in 1848, the U.S. established a series of forts along the Rio Grande to secure the border. Simultaneously, a "first line of frontier forts" were built from Fort Worth southward through this area to defend settlers against Indian attacks. West from this point, across Seco Creek on a high bluff, is the site of old Fort Lincoln, one of the "first line" forts. Established on July 7, 1849, it was named for Capt. George Lincoln who died in the war with Mexico. By 1851, there were barracks for two companies, a hospital and warehouse all constructed of wood. The company commander, Capt. James Longstreet (later a Civil War general) and his men built the fort. In July 1852, the fort was closed because "the frontier had moved west". For 25 years after the fort closed, settlers fought Indians over possession of this land. At times, a small force of Texas Rangers was here to help defend the settlers.