Battle of Glorieta Pass ends the Confederate invasion of New Mexico Territory

Background. The New Mexico campaign was a major Confederate operation in the Trans-Mississippi theater from February to April 1862. Brigadier General Henry Hopkins Sibley aimed to seize the Southwest, including Colorado gold fields and California ports. Union forces in the Department of New Mexico, headquartered at Fort Craig, were led by Colonel Edward Canby, who faced Sibley's Army of New Mexico.

Campaign Context. Sibley's strategy, presented to President Jefferson Davis, sought to establish Confederate control over the American West. In December 1861, Sibley proclaimed possession of New Mexico. In February 1862, he advanced northward from Fort Thorn toward Santa Fe and Fort Union, following the Rio Grande past Fort Craig, where Canby's 3,800-man Union force was garrisoned.

Outcome. Although not the largest battle of the campaign, the Battle of Glorieta Pass ended the Confederacy's efforts to capture New Mexico and other western parts. Union forces defeated Sibley, forcing his retreat to Texas. Historians regard the campaign as the most ambitious Confederate attempt to control the American West and open an additional theater.

Preliminary Engagements. In February 1862, Sibley's Army of New Mexico defeated Canby and his troops at the Battle of Valverde. Separately, on February 20, Union forces advanced from the fort but were hit with heavy Confederate artillery and forced to retreat. The supplied passages do not state the location of the Valverde defeat, so no site is asserted here.