March 1, 1862 – Federal troops abandoned Albuquerque in the face of Brigadier General Henry H. Sibley’s advancing Confederate Army of New Mexico.
With the Confederates were running low on provisions, Sibley gambled by marching them northward, farther from their supply base, in hopes of seizing Federal provisions at Albuquerque. However, town residents learned of the Confederate advance and burned the supplies on the morning of March 1. When Sibley’s men arrived the next day, they found nothing but an abandoned, empty town.
Fortunately for the Confederates, a group of secessionists seized the village of Cubero, 60 miles west of Albuquerque, along with the military supplies there used to defend against Native Americans. Sibley received word of this capture and sent a detachment to collect the bounty, which included arms, ammunition, medical supplies, and camp provisions. This helped enable the Confederates to continue moving northward to the territorial capital of Santa Fé.
Federals stationed at Santa Fé learned of Sibley’s advance and fell back to Fort Union, about 60 miles northeast in the Sangre de Cristo Mountains. This isolated the overall Federal commander in the New Mexico Territory, Colonel Edward R.S. Canby, at Fort Craig, about 250 miles south of Fort Union.
Although Sibley had the run of the New Mexico Territory, there were still 3,500 Federals under Canby in his rear and another 1,300 Federals at Fort Union, one of the strongest fortifications in North America. Sibley opted to ignore both forces, thus leaving the Federals with the strength to take the territory back later. Meanwhile, Federal forces quickly mobilized in California, Kansas, and the Colorado Territory upon learning of Sibley’s offensive.
While Sibley set up headquarters at Albuquerque, a portion of his army occupied Santa Fé soon after it was abandoned. They gathered any supplies that had not been destroyed and used a printing press to distribute a proclamation from their commander. Recounting his victory at Valverde and conquest of both Albuquerque and Santa Fé, Sibley offered amnesty to any Federal soldiers who would “lay aside their arms and return to their homes and avocations” within 10 days.
Colonel Gabriel Paul, commanding the Federals at Fort Union, reported that the situation was “daily growing from bad to worse. All the militia and a large number of the volunteers who were called into the service of the United States have deserted and taken to the mountains.” His communications with Canby at Fort Craig had been cut off for two weeks.
As Paul planned to leave Fort Union to try somehow meeting up with Canby, a message finally arrived: “Do not trust the Mexican troops.” This referred to native Mexicans who had volunteered for Federal service but did not much care for the Federal cause. The message continued: “If the Colorado or Kansas or California troops have not joined you, do not risk an engagement until they do.”
Soon about 900 Colorado troops arrived at Fort Union, along with Colonel John P. Slough, who outranked Paul and became the new fort commander. Slough, a politician with no military experience, had been commissioned colonel just days before Paul, a West Pointer and veteran of the Seminole and Mexican wars. This played a significant role in upcoming operations.
CivilWarDailyGazette.com (multiple dates); Faust, Patricia L., Historical Times Illustrated Encyclopedia of the Civil War (New York: Harper & Row, 1986, Patricia L. Faust ed.), p. 776; Fredriksen, John C., Civil War Almanac (New York: Checkmark Books, 2007), p. 116-17; Josephy, Jr., Alvin M., War on the Frontier: The Trans-Mississippi West (Alexandria, VA: Time-Life Books, 1983), p. 27; Long, E.B. with Long, Barbara, The Civil War Day by Day (New York: Da Capo Press, Inc., 1971), p. 177-78; Pollard, Edward A., Southern History of the War (New York: The Fairfax Press, 1990), p. 288-89; Stanchak, John E., Historical Times Illustrated Encyclopedia of the Civil War (New York: Harper & Row, 1986, Patricia L. Faust ed.), p. 687