New Mexico Campaign

The New Mexico Campaign was a military operation of the American Civil War from February to April 1862 in which Confederate Brigadier General Henry Hopkins Sibley invaded the northern New Mexico Territory in an attempt to gain control of the Southwest, including the gold fields of Colorado and the ports of California. Historians regard this campaign as the most ambitious Confederate attempt to establish control of the American West and to open an additional theater in the war. It was an important campaign in the war's Trans-Mississippi Theater, and one of the major events in the history of the New Mexico Territory in the American Civil War.

The Confederates advanced north along the Rio Grande from Fort Bliss in Texas. They won the Battle of Valverde but failed to capture Fort Craig or force the surrender of the main Union Army in the territory. They continued north across the border towards Santa Fe and Fort Union, leaving that Union force in their rear. At Glorieta Pass, the Confederates defeated another Union force from Fort Union, but were forced to retreat following the destruction of the wagon train containing most of their supplies.

Confederate success in this campaign would have denied the Union a major source of the gold and silver necessary to finance its war effort, and the Union navy would have had the additional difficulty of attempting to blockade several hundred miles of coastline in the Pacific. A Confederate victory would have also diverted Union troops which, following the invasion, were used to fight Native American tribes on the plains and in the Rockies.

Opposing forces
Union forces in the Department of New Mexico were led by Colonel Edward Canby, who headquartered at Fort Craig. Under his immediate command at the fort were five regiments of New Mexico volunteer infantry, a company of the 2nd Colorado Infantry, two provisional artillery units, eleven companies of the 5th, 7th, and 10th U.S. Infantry, six companies of the 2nd and 3rd U.S. Cavalry, and two regiments New Mexico militia. At Fort Union, under the command of Colonel Gabriel Paul, were the 1st Colorado Infantry, a company of the 2nd Colorado Infantry, a battalion of the 5th U.S. Infantry Regiment, a detachment from the 1st and 3rd U.S. Cavalry, a company of the 4th New Mexico Infantry, and two provisional artillery batteries.

The Confederate Army of New Mexico was led by Brigadier General Henry Hopkins Sibley. His units included the 4th Texas Mounted Rifles and 5th Texas Mounted Rifles (both of which had batteries of mountain howitzers), five companies of the 7th Texas Mounted Rifles, six companies of the 2nd Texas Mounted Rifles (which also had an artillery battery attached), and several companies of Arizona Confederate mounted volunteers. Following his arrival in New Mexico in January, Sibley organized his artillery into a battalion under the command of Captain Trevanion Teel, whom he promoted to major. Five additional companies of the 7th Texas arrived near the end of February and served as the garrison of Fort Thorn at Mesilla.

Confederate strategy
For years, residents in the southern part of the New Mexico Territory had been complaining that the territorial government in Santa Fe was too far away to properly address their concerns. The withdrawal of the Regular army at the beginning of the war confirmed to the residents that they were being abandoned. Secession conventions in Mesilla and Tucson voted to join the territory to the Confederacy in March 1861, and formed militia companies to defend themselves. In July 1861, Lieutenant Colonel John Baylor led of a battalion of Texas mounted rifles into the southern portion of the New Mexico Territory, entering Mesilla and repulsing the attack of the Union garrison of Fort Filmore at the Battle of Mesilla. The victorious Baylor established the Confederate Territory of Arizona south of the 34th parallel.

The 1862 campaign was a continuation of this strategy formulated by Sibley in a plan presented to Confederate president Jefferson Davis. Sibley's strategy called for an invasion along the eastern side of the Rocky Mountains, seizing the Colorado Territory (then at the height of the Colorado Gold Rush) and Fort Laramie (the most important United States Army garrison along the Oregon Trail), before turning westward to attack the mineral-rich Nevada and California. He planned to take minimal supplies along with him, intending to live off the land and to capture the stockpiles of supplies at Union forts and depots along the Santa Fe Trail. Once these territories had been secured, Sibley intended to take the northern Mexican states of Chihuahua, Sonora, and Lower California, either through purchase or by invasion.

March toward Santa Fe
On December 20, 1861, General Sibley, in command of the Army of New Mexico, issued a proclamation taking possession of New Mexico in the name of the Confederate States. He called on the citizens to abandon their allegiance to the Union and to join the Confederacy, warning that those "who co-operate with the enemy will be treated accordingly, and must be prepared to share their fate." In February 1862, Sibley advanced northward from Fort Thorn up the valley of the Rio Grande, toward the territorial capital of Santa Fe and the Union storehouses at Fort Union. Along the way, Sibley detached 54 men to occupy Tucson. The Confederate advance followed the west bank of the river via Fort Craig, which was garrisoned by a 3,800-man Union force under Canby. Knowing he could not leave such a large Union force behind him as he advanced, Sibley attempted to lure the Union forces out into battle on favorable terms.

On February 19, Sibley camped at the sandhills east of the fort with the intention of cutting the Union lines of communications with Santa Fe. On February 20, the Union forces advanced from the fort but were hit with heavy Confederate artillery and were forced to retreat. The next day the Confederates marched to Valverde Ford, six miles (10 km) north of the fort, in an attempt to outflank the Union forces. Canby attacked, but the Union forces were driven back by the Confederates under Colonel Thomas Green, who took command after Sibley was indisposed (some say of drunkenness). Canby's forces retreated to Fort Craig but refused to surrender.

Since he had only enough rations for three days, Sibley could not attempt a siege nor retreat back to Mesilla. Instead, he chose to disengage from the fort and continued slowly northward towards Santa Fe, on the other side of the border in New Mexico Territory. Hoping to reach the supplies located there and also to cut Fort Craig's lines of supplies and communications. Due to the loss of horses at Valverde, the 4th Texas had to be dismounted, with the remaining horses, already in a weakened state, distributed among the other units. They also had lost much of their transportation in the battle at Valverde, causing them to carry the wounded. All this caused the column to travel slower than it could have. Canby meanwhile attempted to trap Sibley's army between his own force and Fort Union. He disbanded his militia and most of the volunteer units, and sent most of his mounted units northward to act as partisans and to "obstruct [Sibley's] movements if he should advance, and cut off his supplies, by removing from his route the cattle, grain, and other supplies in private hands that would aid him in sustaining his force."

Starting on February 23, the Confederate forces reached Albuquerque on March 2 and Santa Fe on March 13, but due to their slow advance they failed to capture most of the Union supplies located at these cities. The slow advance also allowed reinforcements from Colorado under the command of Colonel John Slough to reach Fort Union. Since he had been commissioned colonel before Paul was commissioned the same rank, Slough claimed seniority and took command of the fort. Canby had already ordered Paul to "not move from Fort Union to meet me until I advise you of the route and point of junction." After learning of the change in command, Canby told Slough to "advise me of your plans and movements, that I may cooperate." He also instructed Slough to "harass the enemy by partisan operations. Obstruct his movements and cut off his supplies." Slough interpreted this as an authorization to advance, which he did with 1,342 men from the fort's garrison. The Union and Confederate forces meet at the Battle of Glorieta Pass on March 28. The Confederates were able to push the Union force through the pass, but had to retreat following the destruction of their wagon train, which contained nearly all of their supplies and ammunition. Sibley pulled his army back to Albuquerque to await reinforcements from Texas. Slough, receiving orders from Canby to return immediately to Fort Union, also retreated, fearing a court martial if he disobeyed this order. Once he arrived at the fort, he resigned his commission and returned to Colorado, leaving Lieutenant Colonel Samuel Tappan in command of the regiment and Paul in command of the fort.

Canby initially ordered the Union force to retreat back to Fort Union, but after discovering the weakness of the Confederates he ordered a concentration of Union forces; small garrisons were left at Forts Craig and Union, and the main forces were to rendezvous near Albuquerque. With limited supplies and ammunition and outnumbered, Sibley choose to retreat to Texas, leaving Albuquerque on April 12 after a small fight a few days earlier. On April 14, Canby encountered the Confederates at Peralta, where the armies skirmished until 2:00 p.m. when a sandstorm permitted the Confederates to withdraw. The retreat continued through Mesilla to San Antonio, during which hundreds of Confederates straggled and fell behind. A rearguard of four companies of the 7th Texas and several companies of Arizona Confederates (consolidated under the command of Lieutenant Colonel Philemon Herbert as the 1st Arizona Mounted Rifles Battalion) was left at Fort Thorn, commanded by Colonel William Steele. These forces, heavily outnumbered by Union units arriving from California and Kansas, retreated to Texas in early July.

Aftermath
Following the Confederate retreat, units from the Union California Column under the command of Colonel James Carleton occupied several forts in western Texas. Canby was promoted to brigadier general and reassigned to the eastern theater. He was succeeded as commander of the department by Carleton, who was also promoted to brigadier general. The best men from the New Mexico volunteers were formed into the 1st New Mexico Cavalry with Kit Carson in command; the regiment spent the rest of the war fighting Indian tribes in the territory.

Although the Confederates continued to consider Arizona part of the Confederacy and made several plans for another invasion, they were never able to put these plans into execution. Sibley's brigade would be called by many the "Arizona Brigade" and continued to serve in various areas in Texas and Louisiana during the remainder of the war. Sibley would eventually be demoted to directing supply trains in 1863.

Battlefields today
Approximately 678 acre of the Glorieta Pass battlefield are today protected in the Pigeon's Ranch and Canoncito units of the Pecos National Historical Park near Interstate 25. The Valverde battlefield is no longer preserved in its original state, and the only commemoration of the battle is a marker erected by the United Daughters of the Confederacy near U.S. Route 85 in 1936.

In popular culture
The campaign is part of the backdrop for the 1966 motion picture The Good, the Bad and the Ugly.

Decision Games has published two games dealing with the events of the campaign, both in Strategy & Tactics magazine. The first, Rio Grande: The Battle of Valverde, published in issue 143 and designed by Richard Berg and Dave Arneson. The second game was The Civil War in the Far West: The New Mexico Campaign, 1862, published in 2008's issue 252, covered the entire campaign and was designed by Charles Diamond.