After the Mexican War, the U.S. Army was charged with the defense of settlements and with the protection of travelers through Western Texas. On August 20, 1855, Companies H and K of the First Infantry Regiment, led by Captain Stephen D. Carpenter, established Camp Lancaster on Live Oak Creek where they found plenty of clear water near the San Antonio–El Paso Road crossing of the Pecos River. Camp Lancaster was strictly an infantry post and was officially designated a permanent fort on August 21, 1856, one year after its establishment. One of the most isolated posts in Texas, Fort Lancaster’s only civilian activities were a sutler and a stage stop for mail. Soldiers maintained the post, patrolled and protected the road, and occasionally came in contact with Native Americans.
Soldiers constructed the permanent buildings at Fort Lancaster with a combination of limestone blocks and adobe. Stone was used for the foundations, corners, chimneys and sometimes the gable ends of the structure. Adobe bricks were laid in courses to form the walls. Exterior surfaces were plastered smooth, scored to resemble dressed masonry and then whitewashed. The buildings were generally thatched with grass cut from the area, although a few were built later with wooden shingles.
During the days preceding the outbreak of the Civil War, the U.S. Army abandoned Fort Lancaster, ordering the evacuation of all federal troops in the state. Delayed by a lack of transportation, the soldiers of Company K at Fort Lancaster finally abandoned the post on March 19, 1861.
For a time, Confederate troops attempted to maintain the frontier defense. The forts along the Lower San Antonio–El Paso Road were manned by companies of the Second Regiment, the Texas Mounted Rifles, under Col. John S. Ford; however, a revised defensive system in 1862 left Fort Lancaster and other far western forts deserted for the remainder of the war. It was revived in 1867 when Fort Lancaster began serving as a sub-post for the Buffalo Soldiers’ 9th Cavalry assigned to Fort Stockton. In December 1867, 40 soldiers and officers held off roughly 400 Kickapoo with only three casualties.
Today, Fort Lancaster remains the only Texas Army post that was attacked by Native Americans. The site is a State Archaeological Landmark and listed in the National Register of Historic Places. Archaeological excavations from 1966 and 1971 yielded the discovery of artifacts indicating that prehistoric Native Americans lived at the site around 1,000–8,000 years ago.