By 1846 political differences, economic disagreements, and boundary disputes between the United States and Mexico had reached the boiling point. The U.S. government prepared to invade Mexico, and Albuquerque lay in the direct line of march down the Río Grande.

When troops under the command of Gen. Stephen Watts Kearny reached Santa Fe, they learned that secret American envoys had preceded them. The envoys apparently struck a bargain with Gov. Manuel Armijo to retreat to El Paso without engaging the U.S. forces, although written proof has never been discovered.

Kearney marched unopposed into Albuquerque in September 1846, raised the American flag, conferred citizenship on the people, and formally made the village a part of the United States. Residents fired off cannon salutes from the top of San Felipe de Neri Church and held endless fandangos (parties) in honor of the officers and enlisted men.

The U.S. military occupation of Albuquerque proved to be good for civilians. The army set up a supply depot west of the plaza with a contingent of mounted riflemen to protect supply lines to the United States and keep order. A formal post was established on November 17, 1846, which was withdrawn briefly between 1851 and 1852; the troop station was made departmental headquarters in August of 1852.

As soon as soldiers arrived, money began to pour into the local economy. Mercantile houses expanded, saloons multiplied, and contractors provided rental property, wood, fodder for animals, and rations for soldiers. As the number of troops greatly exceeded that of Spanish and Mexican soldiers stationed in Albuquerque during earlier periods, Indian raids came to a halt.

From 1846 until the post closed in 1867, Albuquerque was a military town. Of the 1,608 people here, 1,107 were natives and 501 were foreign born. The latter included more than 400 enlisted men and officers at the post. Most of them were recent immigrants from Germany and Ireland. There were also soldiers and civilians from England, France, Switzerland, Poland, Denmark, Italy, Norway, Turkey, Belgium, and Austria.

It’s not clear where exactly the military post was located. Post headquarters were on the west side of the plaza across Main Street (now Rio Grande Boulevard), between the plaza and the river. The post corral was on the northwest corner of the intersection of present-day Central Avenue and Rio Grande, and the enlisted barracks were somewhere near the river.

For 36 days in 1862, Albuquerque became the Confederate capital of New Mexico. After a bloody battle, a portion of the Fourth Regiment of Texas Mounted Volunteers under the command of General H.H. Sibley failed to take Fort Craig, south of Socorro. In need of supplies, the exhausted troops pushed on to Albuquerque. Union soldiers, meanwhile, had moved everything possible from their Albuquerque post, burned everything remaining, and retreated north under Captain Herbert M. Enos.

The Confederates entered Albuquerque on March 7, held a ceremony to claim the village and New Mexico for the Confederacy, fired a 13-cannon salute and raised their flag on Old Town Plaza. Albuquerque was under its fourth flag in 156 years.

For two weeks, the rebels foraged for food in the Sandia Mountains and relaxed in the plaza. Rumor has it that Sibley commandeered the house belonging to merchant Franz Huning, now the Manzano Day School, southeast of the plaza. Then they marched north to engage Union forces but met with disaster at Glorieta Pass. The Confederates fled back to Albuquerque.

On April 10 there was a minor skirmish when Confederate forces dug in near Franz Huning’s mill, ironically named “La Glorieta,” east of Old Town and exchanged artillery fire with Union forces at nearby Barelas.

After Union forces withdrew, Sibley decided to marshall his men and leave for El Paso. Their last actions were to see that the injured men left behind were provided for in the local makeshift hospital, and to bury eight 12-pound howitzers captured from Union forces in a corral northeast of the plaza. They were later recovered, and two are preserved in The Albuquerque Museum. On April 12 the last of the Confederates left Albuquerque, and the town was once again in Union hands.

Five years later, the Army no longer needed a post in Albuquerque. On August 23, 1867 the post that had protected Albuquerque and stimulated the local economy for more than 20 years was closed. With that, just two of the soldiers recorded on 1860 remained, and only seven of approximately 100 civilians were left.

Many noted military figures were one-time residents of Albuquerque. Gen. Phil Sheridan once rented a building owned by Cristóbal Armijo on the present site of the Blueher House. Maj. James Longstreet, the post’s paymaster, eventually rose to the rank of Lieutenant General and gained fame as Gen. Robert E. Lee’s right hand. Captain Zenas Bliss, reputed to be the first infantry officer to enter the fallen Confederate capital of Richmond, Virginia, moved to Albuquerque in 1887 and taught at the Albuquerque Indian School.

Albuquerqueans also mustered to fight with First U.S. Volunteer Cavalry Regiment, better known as the Rough Riders, during the Spanish-American War of 1898. Known for their ability to ride, shoot and endure harsh conditions, the Rough Riders fought to liberate Cuba from Spain and ultimately won control of Guam, Puerto Rico and the Philippines. Most of the regiment hailed from New Mexico; Corporals Edward Armstrong and Hiram T. Brown were but two who called Albuquerque their home.