Army of the Trans-Mississippi

The Army of the Trans-Mississippi was the major Confederate field army for the Department of the Trans-Mississippi during the American Civil War. It was the last major Confederate command to be surrendered and the site of the post-war Battle of Palmito Ranch—a Confederate victory fought in late May 1865 — several weeks after the war had actually ended.

Overview
The Department of the Trans-Mississippi had been separated from the Western Department on May 26, 1862. It primarily consisted of the four Confederate states west of the Mississippi: Texas, Louisiana, Arkansas, and Missouri; as well as the two Confederate territories: Indian Territory and Confederate Arizona (roughly corresponding to the present-day states of Oklahoma, New Mexico, and Arizona). The command of the area was given to Major-General T. H. Holmes.

Trans-Mississippi was the operational theater for many quasi-independent forces, including Quantrill's Raiders, and the Missouri Bushwhackers.

The army
The Army of the Trans-Mississippi was the major Confederate field army for the Department of the Trans-Mississippi during the American Civil War. The army originally numbered well over 50,000 troops, but less than 43,000 were mustered at the war's conclusion. Major campaigns fought in this department included Sibley's New Mexico campaign, Banks' Red River campaign, and Price's Missouri campaign.

Additionally, the Army of the Trans-Mississippi was the last major Confederate command to surrender. General E. Kirby Smith did so on May 26, 1865, although many of his troops had already "gone home."

It was in Trans-Mississippi that the post-war Battle of Palmito Ranch was fought on May 12–13, 1865. A victory for the Confederate forces, the battle was actually fought several days after the war had ended. Although the war in Trans-Mississippi was officially over, the declaration of the end of hostilities could not yet be counted on. The last remaining Confederate land-combat force of the war, the 1st Cherokee Mounted Rifles (led by Cherokee Nation leader, and Confederate Brigadier-General, Stand Watie) surrendered on June 23, 1865.

Organization

 * Trans-Mississippi Army, I Corps (Headquartered at Shreveport, Department of Louisiana)
 * This corps was organized under the command of Simon Bolivar Buckner


 * Trans-Mississippi Army, II Corps (Department of Arkansas and Missouri)
 * This corps was organized on August 4, 1864 under the command of John B. Magruder.


 * Trans-Mississippi Army, III Corps (Headquartered at Galveston, Department of Texas)
 * This corps was organized on August 4, 1864 under the command of John George Walker.


 * Trans-Mississippi Army, Cavalry Corps
 * The Cavalry Corps was organized on August 4, 1864 under the command of Sterling Price.


 * Trans-Mississippi Army, Reserve Corps
 * The Reserve Corps was established on September 10, 1864 to support the Trans-Mississippi Army.