With the end of World War I in 1918, the Air Service, United States Army was largely demobilized. During the demobilization period of 1919, the Regular Army and its air arm answered a call to defend the southern border against raids from Mexico, and to halt smuggling of illegal aliens and narcotics into the United States and weapons from the United States into Mexico.

Fort Bliss is a United States Army post in New Mexico and Texas, with its headquarters in El Paso, Texas. Named in honor of LTC William Bliss (1815–1853), a mathematics professor who was the son-in-law of President Zachary Taylor, Ft. Bliss has an area of about 1,700 square miles (4,400 km2); it is the largest installation in FORSCOM and second-largest in the Army overall. The portion of the post located in El Paso County, Texas, is a census-designated place with a population of 8,591 as of the time of the 2010 census. Fort Bliss provides the largest contiguous tract of restricted airspace in the Continental United States, used for missile and artillery training and testing, and at 992,000 acres boasts the largest maneuver area. The garrison's land area is accounted at 1.12 million acres, ranging to the boundaries of the Lincoln National Forest and White Sands Missile Range in New Mexico. Fort Bliss also includes the Castner Range National Monument.