On March 28, 1862, Union and Confederate troops fought the key battle of the Civil War in the far West at Glorieta Pass, New Mexico. The Confederates were Texans of Brig. Gen. Henry Hopkins Sibley's Army of New Mexico, which had invaded the Union Territory of New Mexico. After taking Fort Fillmore, near Mesilla, and winning the battle of Valverde on February 21, 1862, the Texans continued northward along the Rio Grande, occupying the towns of Albuquerque and Santa Fe during early March. There they delayed to gather provisions for a further advance on Sibley's primary objective, Fort Union, the federal supply center some 100 miles northeast of Santa Fe, on the Santa Fe Trail and on the route to the gold mines around Denver City, Colorado Territory.
The Union force was a regiment of frontiersmen from the mining districts around Denver City, the First Colorado Volunteers, commanded by Col. John P. Slough, a Denver lawyer. These "Pike's Peakers" were augmented by detachments of cavalry and infantry from the garrison of Fort Union. On March 22 Slough led his field column of 1,340 men out of Fort Union toward the Texans, known to be in the vicinity of Santa Fe.
From his headquarters in Albuquerque Sibley sent his main field column through the mountains toward Fort Union, while a smaller force, under Maj. Charles L. Pyron, occupied Santa Fe. Pyron learned of the federals' approach and, on March 25, led his men eastward along the Santa Fe Trail to find the enemy. His 400-man force left camp at Cañoncito early on the morning of March 26 and encountered Slough's advance guard, about 420 men under the command of Maj. John M. Chivington, moving westward on the same road. The Texans formed a battle line across the road, but the Union forces outflanked the line by climbing the hillsides bordering the Santa Fe Trail. Thereupon, the Confederates withdrew westward toward Apache Canyon, a small valley of cultivated fields, and established a second, and probably a third, similar battle line. Chivington repeated his flanking tactic and, in addition, sent a furious cavalry charge against the Texan positions. Seventy Confederates were captured during this battle of Apache Canyon. About four others were killed, and twenty were wounded. Pyron retreated to his camp at nearby Cañoncito and sent an urgent request for assistance to the Texan main column, camped fifteen miles away. Major Chivington, with five men killed and fourteen wounded, broke off the action and retired to the main Union camp at Koslowski's Ranch, a Santa Fe Trail station twelve miles away from the Texans.
On the morning of March 28, the Confederates, under Lt. Col. William R. Scurry, again marched eastward, leaving their supply train at Cañoncito guarded by a handful of noncombatants with a single cannon, and advancing on Fort Union and its vital supplies. About eleven o'clock scattered shots opened the battle of Glorieta, as the 1,200 Texans encountered Colonel Slough's 850-man force resting and filling canteens at Pigeon's Ranch, a Santa Fe Trail hostelry one mile east of Glorieta Pass. The rest of Slough's troops, 490 men led by Major Chivington, had earlier left the main force to attack the Texan camp at Cañoncito. Chivington was pushing his men across a heavily wooded mesa south of the trail when the main columns met near Glorieta. The two forces exchanged fire across the Santa Fe Trail until about two o'clock, when Scurry outflanked the Union line, forcing Slough to withdraw to a second defensive line near Pigeon's Ranch. The Texans gained heights above the federal troops and forced Slough to withdraw to a third position a half mile to the east. The Confederates followed, and the two sides exchanged desultory cannon and small-arms fire. Slough withdrew to his camp at Koslowski's Ranch, some five miles to the rear, leaving Scurry in possession of the field.
As the battle raged around Pigeon's Ranch, however, Major Chivington's party had reached a point some 200 feet directly above the Texans' wagon park and camp at Cañoncito. They descended the steep slopes, disabled the cannon left at the site, and burned the entire eighty-wagon supply train containing Scurry's reserve ammunition, baggage, food, forage, and medicines. The federals retraced their route and rejoined Slough's main force at Koslowski's Ranch after dark. That phase of the battle of Glorieta sealed the fate of the Confederate invasion of New Mexico.
The battle of Glorieta ended in the darkness around Pigeon's Ranch. The Texans had lost forty-eight killed and sixty wounded, and the Union forces had taken almost identical casualties. Slough's men returned to Fort Union, while Scurry remained at Pigeon's Ranch for another day, treating his wounded and burying his dead in a mass grave across the Santa Fe Trail from the hospital. Although both sides claimed victory, the Union coup at Cañoncito forced Sibley's withdrawal from New Mexico and checked the Confederate advance in the far West.
In June 1987 excavation for a house foundation turned up the mass grave, which contained the remains of thirty-one Confederate soldiers. Forensic techniques led to the identification of three of them. After some debate about where the bodies should be reinterred-in Texas, where the men came from, in New Mexico at the site of the battle, or elsewhere-most of the fallen soldiers were buried at the National Cemetery in Santa Fe.