Fort Fillmore was originally constructed in the
jacal style with upright wood posts plastered over with adobe; later, more substantial adobe walls were erected. Much of the work on the fort was done by the soldiers with the assistance of local Mexican laborers who made the adobe bricks. The post was built on sand hills above the
Rio Grande. The Rio Grande would later change its course, making the fort about 1 mile from the river. This forced the army to use water wagons to supply the post with water and made it hard to defend in the event of attack. Fort Fillmore served as an operating base for units of the
1st Dragoons, briefly the
2nd Dragoons,
Regiment of Mounted Rifles, and the
3rd and briefly the
8th Infantry Regiments. It was for a time the headquarters of the 3rd Infantry Regiment. The troops were active in the
Gila Expedition of 1857 and in operations against the Apaches in the
Sacramento Mountains. In one foray, Captain Henry W. Stanton, namesake of
Fort Stanton, New Mexico, was killed near the Rio Penasco. His grave was one of the few to be identified when the abandoned post was inspected in 1869. Most of the soldiers and civilians interred in the fort's cemetery are still buried there on a sand ridge southeast of the remains of the fort. A fence and flagpole are now located on the cemetery's site. Fort Fillmore was a stop on the
Butterfield Overland Mail. Possibly the most famous soldier who served at Fort Fillmore was Captain
George Pickett. Pickett is best remembered for leading the
fateful charge on July 3, 1863 at the
Battle of Gettysburg. In 1855, Union General
Ambrose Burnside used the fort as a supply point when he drilled geothermal wells about fifteen miles west of the post.. ==Abandonment==