In the summer of 1861 Lt. Col. John R. Baylor led a small band of Texans in occupying the Mesilla Valley in southern New Mexico. By December 1861 a much larger 3,000-man Texan Army began to arrive at Franklin (El Paso) and move north to join Baylor. In command of the Confederate Army of New Mexico was Brig. Gen. Henry H. Sibley, a twenty-two year veteran of the antebellum army, who had been stationed in New Mexico prior to the war. Sibley's objective, although never clearly defined, appears to have been Colorado and eventually California, thus making the Confederacy a transcontinental nation more likely to win diplomatic recognition in Europe. In early 1862 Sibley moved against Fort Craig, a Federal bastion in south-central New Mexico. By February 16 the Texan army had pushed to within a mile of the post. At the fort a Union force of 1,250 Regulars and 1,350 hastily recruited New Mexico volunteers and militia awaited the Rebel advance. All were commanded by Col. Edward Richard Sprigg Canby. Realizing that Fort Craig was too well fortified to be taken by assault, Sibley offered battle on the open plain south of the fort. When Canby refused, Sibley decided to bypass the fort by retreating downriver some seven miles to the village of Paraje, where the Rebels crossed to the east bank of the Rio Grande. Sibley miscalculated that it would take his army one day to reach the Valverde Ford, some six miles upriver from Fort Craig, where the Rebel army could then recross the river. Slowed by deep sand, the Texans were forced to make a dry camp on the evening of February 20. Realizing that the Valverde Ford was Sibley's objective, Canby sent a battery of artillery and two regiments of volunteers across the river to impede the Texan advance. Although Canby ordered his army into battle position and sent out skirmishers, the Union force was driven off by the Rebel artillery.
At daybreak on Friday, February 21, 1862, Sibley sent Maj. Charles L. Pyron with 180 men to reconnoiter a road to Valverde. Pyron was followed by Maj. Henry R. Raguet with five companies. Pyron rode north along the eastern extremities of Black Mesa before turning west along the north edge of the escarpment to the river. Reaching a small cottonwood grove near the ford, the Rebels commenced watering their horses when Pyron discovered a force of Federal cavalry in his front. As the Texans took cover in the sandy bottomland, a fierce firefight erupted. In response, Canby hurried Col. Benjamin S. Roberts with regular and volunteer cavalry to the scene. Hearing the same gunfire, Major Raguet, joined by Col. William R. Scurry and the remainder of the Rebel Fourth Regiment, also raced for the river. By ten o'clock, a section of Capt. Trevanion T. Teel's artillery had also reached Valverde. Several times the Texans advanced toward the river, only to be driven off by a heavy Union artillery bombardment. About this time Union forces moved to envelop the Rebel right by crossing the Rio Grande upriver from Valverde. Such a move forced Scurry to divide his command and lengthen the Confederate line. For two hours Capt. Alexander McRae, a North Carolinian who had remained loyal to the Union, continued to pound the Rebel position on the east bank with his artillery. By eleven o'clock it was evident to Colonel Scurry that the Rebels would have to withdraw. Retreating from the bosque and the east bank of the river in confusion, the Texans were able to take refuge behind a low ridge of sandhills that paralleled the east bank of the river. By midday the tide of battle was clearly swinging in favor of the Federals.
By one o'clock, as additional units, both Union and Confederate, raced for Valverde, General Sibley had become so ill, exhausted, and drunk that he had retired to an ambulance in the Confederate rear, and the Rebel army was turned over to Col. Thomas Green. On the Rebel right, Capt. Willis L. Lang with a company armed only with lances, launched a gallant and courageous attack against a company of Colorado Volunteers that had been hastily recruited and hurried south from Denver. The Coloradoans held their fire until the Lancers were within a few yards of the Federal line and then fired a deadly volley into the charging Rebels. In the suicidal attack, the Lancers, Company B of the Fifth Regiment, suffered a greater loss of life than any other company in the Army of New Mexico. Captain Lang was so severely wounded that he later committed suicide. Lt. Demetrius M. Bass, Lang's second in command, was wounded several times and died several days later. Shortly after three in the afternoon, Colonel Canby arrived on the battlefield and decided to advance his right and center while using his left as a pivot, thus forcing the Rebel left. To reinforce his army Canby ordered Colonel Christopher (Kit) Carson's regiment of volunteers across the river. At the same time Colonel Green decided on an all-out attack on the Federal artillery. Concealed by the sandhills, Green advanced on the Union center as Colonel Raguet moved against a Federal battery firing on the Rebel left flank. Raguet's cavalry advanced to within 100 yards of the Union guns before being driven off. Green's advance on the right, however, proved to be the decisive maneuver of the battle. Although McRae's battery poured a deadly fire of grapeshot into the charging Texans, the Rebels fell upon the Union artillery with a hand-to-hand savagery rarely seen in the annals of American military history. Within eight minutes the Texans had overrun the Union guns. McRae and half of his men died at their guns. In fact, eighty percent of the men killed and wounded in the Federal ranks fell at or near McRae's battery.
Canby blamed the loss of McRae's battery on the New Mexico Volunteers, who he argued had refused to obey orders in counterattacking the lost guns. With the Union line in disarray and snow falling lightly, other Union troops fled for the Rio Grande, many dropping their weapons in their haste. A number of the Federals were killed while attempting to cross the river. As the Union forces retreated to the safety of Fort Craig, Colonel Canby sent a white flag into the Rebel lines. Rebel commanders at first thought Canby was offering to surrender, but he asked only for a cessation of hostilities to remove the Federal dead and wounded. Union casualties at Valverde amounted to 222 men killed and wounded, while the Confederates lost 183. On the day following the battle, the Rebel dead were wrapped in blankets and buried in trenches. Federal dead were interred at Fort Craig. Although the Rebel Army of New Mexico had won the field at Valverde, the largest Civil War battle in the Rocky Mountain West, they had failed to take Fort Craig. After occupying Albuquerque and the territorial capital of Santa Fe, Rebel forces again won the field in the battle of Glorieta on March 28, 1862, but were forced to retreat when Colorado Volunteers destroyed their supply train in Apache Canyon. In April Sibley ordered a retreat to the Mesilla Valley. By summer the Confederate Army of New Mexico was in full retreat back to San Antonio. The Sibley campaign had proved to be a disaster.