Few casual readers of American history are aware of Fort Union, New Mexico, and its history. Many would probably confuse it with another Fort Union, on the headwaters of the Missouri also important, but not as vital to the history of the West as the Fort Union near Las Vegas, New Mexico.
It was inevitable that the United States would dominate the Southwest. The military was used to achieve this goal, and the story of military operations in the Southwest is centered on Fort Union. Founded in 1851, the fort was the supply post and focal point for dealing with the Spanish and Indian populations in New Mexico Territory until it was abandoned in 1891.
During the Civil War, Fort Union was the final objective in the Confederates' advance into New Mexico. Confederate General Henry H. Sibley had supervised the construction of its arsenal some years earlier and was determined to capture its great store of military supplies. Moreover, its conquest would put the Confederates a step nearer to the gold mines in Colorado. But the Battle of Glorieta Pass put an end to such ambitions, and Fort Union remained a stronghold for the Union Army in the western territories.
After the Civil War, the fort was charged with maintaining peace among the Indian tribes of the area until its detachment was transferred to Fort Wingate in 1891. Declared a National Monument in 1954, the remains of Fort Union are now under the care of the National Park Service."
Fort Union and the Winning of the Southwest
University of Oklahoma Press