March 26–28, 1862
Often referred to as the Gettysburg of the West, the Battle of Glorieta Pass, fought on March 26-28, near Santa Fe, New Mexico, was the decisive turning-point of the American Civil War in the Far Western Theater.
Soon after the American Civil War erupted, Confederate officials began making plans to annex the New Mexico Territory and to extend their authority to the Pacific Ocean via California. As early as June 1861, Lieutenant Colonel John Baylor led a small band of Rebel soldiers out of Central Texas toward El Paso and forced the surrender of Fort Bliss on July 1. From there, he marched three hundred miles up the Rio Grande into New Mexico and forced the evacuation of Fort Fillmore on July 26. Five days later, Baylor, apparently satisfied with the extent of his conquest, trumpeted the establishment of the Arizona Territory, and appointed himself as the governor.
In response to Baylor's actions, on November 9, 1861, the United States War Department issued General Orders No. 97, creating the military Department of New Mexico, "to consist of the Territory of New Mexico – to be commanded by Colonel E.R.S. Canby, U.S.A." Hoping to repulse a deeper invasion into the territory, Canby established his departmental headquarters at Fort Craig, near the Rio Grande, nearly 170 miles north of the Texas border. He then went about recruiting volunteers to repel the Confederate intruders. Alarmed by the invasion of their homeland, many native New Mexicans rallied to join the Union volunteer army. As news of a second invasion became more certain, Canby wired the territorial governor of Colorado, William Gilpin, on January 1, 1862, to send, "as large a force of the Colorado Volunteers as can possibly be spared" to assist in defending the New Mexico Territory.
The second Confederate offensive against New Mexico came when Brigadier-General Henry Hopkins Sibley led his Army of New Mexico (also known as Sibley's Brigade) out of Texas in early 1862. Sibley's force consisted of approximately 2,600 soldiers from the 4th, 5th, and 7th Texas Volunteer Cavalry. Sibley's broad objectives were to subdue the remaining Union garrisons in New Mexico, to seize their supplies, to travel up the Santa Fe Trail to capture the Colorado gold fields, and then, to head west to conquer California.
As Sibley entered New Mexico, Canby concentrated his forces at Fort Craig, just south of Socorro. On February 21, led by Lieutenant Colonel William R. Scurry, Canby's volunteers engaged Sibley's raiders at the Battle of Valverde, near Fort Craig. During the course of the confrontation, the Rebels made a frontal assault that breached the Union lines and forced the Federals to fall back to Fort Craig. Rather than pressing the engagement, Sibley bypassed Fort Craig and continued to march north along the Rio Grande, leaving Canby isolated from the remainder of his department. With little opposition in front of him, Sibley occupied Albuquerque on March 2, and the territorial capital at Santa Fe on March 10.
Sibley’s next objective was to subdue Fort Union, a major Federal supply depot located adjacent to the Santa Fe Trail in northern New Mexico. Upon learning that Canby was isolated at Fort Craig in February, Colonel Gabriel R. Paul assumed command of the Federal forces at Fort Union. On March 10, Colonel John P. Slough arrived at the fort leading 950 soldiers of the 1st Regiment of Colorado Volunteers to reinforce the existing garrison of 850 men. Being senior in command, Slough assumed command from Paul.
Almost immediately, Slough and Paul disagreed about how to deal with Sibley. Paul urged Slough to follow Canby's latest orders to stay put and to defend Fort Union. Slough favored marching off toward Santa Fe to engage the Confederates on the battlefield. Being in command, Slough prevailed. On March 22, 1862, he led 1,300 men out of Fort Union, headed toward Sibley's headquarters at Santa Fe. As Slough headed west, Sibley dispatched Major Charles Pyron's Fifth Texas Regiment east along the Santa Fe Trail toward Fort Union.
By March 25, both armies were in the vicinity of Glorieta Pass, a gap in the Sangre de Cristo Mountains southeast of Santa Fe. The next day, nearly four hundred Federals, commanded by Major John M. Chivington, engaged approximately three hundred Rebels, led by Major Charles L. Pyron at Apache Canyon on the west end of the pass. After outflanking his opponent several times, Chivington ordered a frontal attack that scattered the Confederates and forced them to retreat from the pass. Chivington then settled down and awaited the arrival of Slough and the main Union force.
March 27 saw no fighting, as both sides reinforced. By the end of the day, Slough had rejoined Chivington, bringing the number of Union soldiers available for combat to approximately 1,300. The Confederates, led by Lieutenant Colonel William R. Scurry, fielded nearly 1,100 men.
On the morning of March 28, 1862, both commanders in the field ordered an assault. As Scurry moved his men east through Glorieta Pass to engage the Federals, Slough divided his army. The Union commander ordered two infantry battalions, totaling nearly four hundred men, under the direction of Chivington, to circle around the Rebels as they advanced and to hit them in the flank. As the Texans, who now enjoyed a numerical advantage, advanced through the pass, Slough attacked with the remainder of his force at approximately 11 a.m. The two sides fought for nearly five hours. Gradually, the Confederates pushed Slough's forces eastward, before prompting the Federals to retreat, leaving the Rebels in possession of the field by sundown.
Unbeknownst to Scurry, while he was winning the battle, he was losing the campaign. By the time Chivington arrived in position to attack Scurry's flank, the Texans had advanced so far through the pass that they exposed their rear. At the urging of two regular army captains, William H. Lewis and Asa B. Carey, Chivington ordered an assault on Scurry's supply train. The Federals sacked and burned roughly eighty wagons of stores and ammunition, spiked several pieces of artillery, and drove off hundreds of horses and mules before rejoining Slough.
Slough and Scurry spent the next day assessing their losses and burying their dead. The Union suffered an estimated 122 casualties (thirty-eight killed, sixty-four wounded, and twenty captured). The Confederacy lost 121 soldiers (thirty-six dead, sixty wounded, and twenty-five captured). Without supplies and ammunition, any further advance against Fort Union was out of the question, so Scurry retreated to Santa Fe on March 31, to rejoin Sibley.
With Canby still at his rear and no means to sustain his army in hostile territory, Sibley was forced to begin withdrawing from New Mexico. With Sibley in retreat, Canby resumed control of all of the troops in his department. When Slough returned to Fort Union in early April, Canby charged him with disobeying orders for leading the expedition to Glorieta Pass, despite the success of his operation. On April 9, 1862, Slough resigned his position with the Colorado unit and moved east, where he eventually became a brigadier-general in the volunteer army.
On April 14, 1862, while pursuing the retreating Texans, Canby's troops surprised a Confederate regiment encamped near the village of Peralta, approximately twenty miles south of Albuquerque. Although there were few casualties, the Federals captured more of Sibley's dwindling supplies in this last engagement of the New Mexico Campaign. By July, all of the Texans had evacuated the territory, and New Mexico remained in Union control for the duration of the war. Because it was the decisive turning-point of the Civil War in the Far Western Theater, many historians refer to the Battle of Glorieta Pass as the Gettysburg of the West.