Fort Union National Monument, NM


Fort Union sits in ruins on the plains of eastern New Mexico and has a story to tell. The adobe ruins that are visible from quite a distance are the third iteration of Fort Union. Located strategically on the Santa Fe Trail, the fort played an important role in the history of the western movement and the settlement of the Southwest. We’ve visited other forts from the same time period but the size and scope of activity of this fort were particularly impressive.

Following the Treaty of Guadalupe Hidalgo in 1848 establishing U.S. possession of New Mexico, a permanent military presence was necessary to protect communication and supply lines and to solve the pressing problem in the territory of raiding bands of Indians. Fort Union was begun in July of 1851. The first Fort Union, thrown up as quickly as possible by soldiers on duty there, was primarily built of green logs. With no stockades or breastworks of any kind, Fort Union resembled a frontier village more than a military outpost. In August of 1853, Fort Union had a fighting strength of three officers and 164 men. Military campaigns were mounted in 1854, 1855 and 1860-61 but future events in “the States” soon overshadowed these. Issues of slavery and states’ rights were in the forefront.

The beginning of the Civil War brought changes to Fort Union. Several Fort Union officers, including Fort commander Maj. Henry Hopkins Sibley, resigned their commissions and joined the Confederacy. Fear of an impending Confederate invasion brought about the abandonment of the first fort as its location at the base of bluffs was untenable and the structures were in a state of decay.


The second Fort Union was an earthen structure known as the “Star Fort” because of the eight points of its perimeter. The raised outlines of the breastworks are still visible today. Once again, structural problems became a huge issue caused by a combination of unskilled soldier labor and inferior materials. The quarters were so bad that most of the garrison lived in tents outside the structure. In addition, the fort was still not located far enough from those same bluffs to be out of range of cannon fire. Fortunately for them, the fort never came under attack.

In March of 1862, a Confederate force, led by former Fort commander Henry Hopkins Sibley, planned to attack Fort Union, commandeer the supplies there and establish a Confederate empire in the Southwest. On their way to Fort Union, the Confederates were defeated at the Battle of Glorieta Pass, primarily because of a surprise Union flanking movement that destroyed their entire supply train. The Confederates retreated back to Texas.

In August of 1862, plans for a third and final Fort Union were approved. This fort was completely different than its predecessors. It was built on stone foundations and erected with adobe bricks in what is now known as Territorial-style architecture. Work on the fort continued during the Civil War even though most of the regular army units were called to the East. Primarily garrisoned by volunteer units, the third Fort Union was completed in 1867.

Fort Union was located near the junction of the Mountain Route (Raton Route) and the Cimarron Route of the Santa Fe Trail. It was the largest fort west of the Mississippi River and served as supply depot not only for wagon trains on the Trail but also for forty to fifty smaller forts in about a five-hundred-mile radius.

Fort Union was a very active, busy place. The third Fort Union was built to accommodate four companies of soldiers and later expanded to house six companies. Over the years units of the 3rd Cavalry, 8th Cavalry, 15th Infantry and 37th Infantry served there. Beginning in 1876, Fort Union became home to four companies of the 9th Cavalry, the “Buffalo Soldiers.”


The military portion of the fort, the quartermaster depot, and the ordnance depot (arsenal) were very distinct and separate entities. The arsenal was located on the abandoned site of the first Fort Union to be at a safe distance from the main activity area. The parade ground, barracks, officers’ quarters, offices, fort prison, fort chapel and other buildings occupied the military portion.


The quartermaster depot supplied men, horses, wood fuel, forage for livestock, food supplies, munitions of war, and pretty much anything else needed. The vast collection of warehouses, workshops, and corrals was a hive of constant activity. Hundreds of civilians were employed every year.

The arrival of the Atchison, Topeka and Santa Fe railroad over Raton Pass and into Santa Fe early in 1880 closed the era of the Santa Fe Trail and heralded the end for Fort Union. The Fort hung on until it was finally abandoned early in 1891.

The Army had leased the land from private owners and it reverted to the holders of the land title. The post was scavenged for windows, doors and lumber and, within a few years, became a collection of adobe ruins. Efforts to preserve the ruins began in 1929 and continued for the next 25 years.


In 1934, 89-year-old Marian Sloan Russell made a trip down the old Santa Fe Trail in search of memories of her youth. She had lived at Fort Union as a very young woman, met her future husband there and was married in the fort’s military chapel. Of that last visit, she said, “I found crumbling walls and tottering chimneys.” She saw activity tearing down the old fortifications and wrote, “Why not let the old walls stand.” Her wish came to fruition on June 28, 1954, when President Dwight D. Eisenhower signed into law the bill establishing Fort Union National Monument.

Today, the adobe ruins evoke a feeling of that bygone era. Ruts of the Santa Fe Trail are still visible and somehow, if you stand very quietly and listen carefully, you can almost hear the crack of the whips, the straining of harness, the clang of the blacksmith’s hammer, the shouts of men, the cadence of marching feet, and the sound of the bugle over the parade ground.


For more information:

Gardner, Mark L. Fort Union National Monument. Tucson, AZ: Western National Parks Association, 2005.

Houk, Rose. The Guide to National Parks of the Southwest. Tucson, AZ: Western National Parks Association, 2014.

Russell, Marian Sloan, Land of Enchantment: Memoirs of Marian Russell Along the Santa Fe Trail. 1954, reprint ed. Albuquerque, NM: University of New Mexico Press, 1981.

For other pages pertinent to this time period:

Fort Smith National Historic Site

Washita Battlefield National Historic Site

Fort Union Trading Post National Historic Site, ND

Boggsville Historic Site, Colorado

Bent’s Old Fort

Pecos National Historical Park