The Battle of Glorieta Pass was fought March 26–28, 1862, in the northern New Mexico Territory, by Union and Confederate forces during the American Civil War.

Confederate forces sought to break the Union's possession of the West along the base of the Rocky Mountains, with the ultimate aim of controlling strategically valuable mines, railroads, and cities throughout the region.

Although the Confederates were able to push Union forces back through the pass, they had to retreat when their supply train was destroyed and most of their horses and mules were killed or driven off.

Following secession moves by residents,[8]: pp.40–41  Confederate forces seized Mesilla and captured the federal troops there, who made a halfhearted attempt to retreat to Santa Fe.

Canby remained at Fort Craig, hoping to cut Sibley's logistical support from Texas and awaiting reinforcements before he dared to take the offensive.

Sibley sent six companies under the command of Col. Tom Green to block the eastern end of Glorieta Pass, turning any Union defensive position in the Sangre de Cristos.

Pyron retired about 1.5 miles (2.4 km) to a narrow section of the pass and formed a defensive line before Chivington's men appeared.

Chivington ordered a mounted Colorado company to make a frontal charge against the artillery; this succeeded in capturing several Confederates and scattering the rest.

Thinking that Slough would attack again and expecting Green to arrive in the Union rear at any time, Scurry chose to remain in place for the day, digging rifle pits.

[7] With the sounds of battle echoing in the distance, Lt. Col. Manuel Chaves of the 2nd New Mexico Infantry, commander of the New Mexican volunteers, informed Maj. Chivington that his scouts had located the Confederate supply train at Johnson's Ranch.

After watching the supply train for an hour, Chivington's force descended the slope and attacked, driving off or capturing the small guard with few casualties on either side.

[30] They then looted and burned 80 supply wagons and spiked the cannon, either killing or driving off about 500 horses and mules before returning with their prisoners to Kozlowski's Ranch.

[31] With no supplies to sustain his advance, Scurry had to retreat to Santa Fe, the first step on the long road back to San Antonio, Texas.

[citation needed] Parts of the Glorieta Pass Battlefield are preserved in Pecos National Historical Park and are the site of an annual NPS Civil War Encampment event commemorating the battle.

Many Santa Fe residents credited James L. Collins, a Bureau of Indian Affairs official, who had suggested the roundabout attack on the supply train.

On January 23, 1864, the New Mexico Territorial Legislature adopted a resolution that did not mention Chivington and instead asked President Lincoln to promote William H. Lewis and Asa B. Carey, both regular army officers, for "distinguished service" in the battle.

On March 8, the Rio Abajo Press of Albuquerque complained about "Col. Chivington's strutting about in plumage stolen from Captain William H. Lewis" (it did not mention Carey).

[33] A more serious charge made against Chivington was that if he had hurried to reinforce Slough as soon as he heard gunfire coming from Pigeon's Ranch, his 400 men might have been enough to win the battle for the Federals, especially if he had attacked Scurry's flank as he had been ordered.

"[35] Despite the fact that the Confederates took the field, they were forced to retreat to Santa Fe due to the destruction of their supplies and eventually abandon New Mexico Territory.

[36] Further, the battle at Glorieta foiled Sibley's plan to obtain his key objective - the capture of the federal base at Fort Union.

[42] The commission was tasked with identifying the nation's historically significant Civil War sites, determining their importance and providing recommendations for their preservation to Congress.

[citation needed] Of the roughly 10,500 actions of the U.S. Civil War,[43] 384 (3.7%) were identified by the commission as principal battles and rated according to their significance and threat of loss.

[47] The 1966 Sergio Leone film The Good, the Bad and the Ugly refers obliquely to the battle, setting one scene during the post-battle retreat of Sibley's men.

[citation needed] The journey of Scurry's Confederate and Slough's Union forces to the battleground, as well as a detailed narrative of the fight, are described in Tom Bensing's 2012 novel Silas Soule, A Short, Eventful Life of Moral Courage.