Army of the Trans-Mississippi
||This article may require copy editing for grammar, style, cohesion, tone, or spelling. (September 2013)|
|Active||September 28, 1862 - May 26, 1865|
|Country||Confederate States of America|
|Branch||Confederate States Army|
The Army of the Trans-Mississippi was a major Confederate army under the Department of Trans-Mississippi during the American Civil War. It was the last major Confederate command to surrender, exactly one month after Gen. Joseph E. Johnston had surrendered in the eastern United States. The Trans-Mississippi fought in the Battle of Palmito Ranch, a Confederate victory fought in late May 1865. 
The Department of the Trans-Mississippi was separated from the Western Department of the Confederacy on May 26, 1862. It consisted primarily of the four Confederate states west of the Mississippi: Texas, Louisiana, Arkansas, and Missouri and included 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. The Trans-Mississippi was the operational theater for many quasi-independent forces, including Quantrill's Raiders and the Missouri Bushwhackers.
The Army of the Trans-Mississippi originally numbered well over 50,000 troops, but less than 43,000 were mustered at the war's end. Major campaigns included Sibley's New Mexico campaign, Banks' Red River campaign, and Price's Missouri campaign. General E. Kirby Smith surrendered on May 26, 1865, although many of his troops had already gone home.
On May 12 and 13, 1865, the post-war Battle of Palmito Ranch was fought. It was a victory for the Confederate forces, though the battle was actually fought several days after the war had ended. 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, the same month that Gen. J.O. Shelby led his command across the Rio Grande into Mexico rather than surrender.
- Trans-Mississippi Army, I Corps (Headquartered at Shreveport, Department of Louisiana)
- Trans-Mississippi Army, II Corps (Department of Arkansas and Missouri)
- Trans-Mississippi Army, III Corps (Headquartered at Galveston, Department of Texas)
- 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.
- Symonds, Craig L. Joseph E. Johnston: A Civil War Biography. New York: W. W. Norton, 1992. ISBN 978-0-393-31130-3.
- Southern Army- Trans-Mississippi Army; article at civilwarhome.com; retrieved March 2013.
- Eicher, John H. (2001). Civil War High Commands. Stanford University Press. pp. 891–892. ISBN 0-8047-3641-3.
- REBEL TRANS-MISSISSIPPI ARMY.; Strength of the Rebels, What they are Doing, Affairs in Texas; & c. Forrest and Dick Taylor Whipped.; April 9, 1865 article (transcribed); NY Times; retrieved March 2013.
- The Break-up of the Confederate Trans-Mississippi Army, 1865; treatise; Clampitt, Brad R; University of North Texas publisher; Denton, Texas; 2001.