The Army of the Frontier was a Union army that served in the Trans-Mississippi Theater during the Civil War. It fought in several minor engagements in Arkansas, Indian Territory, and Kansas. In June 1863 the Army was discontinued but many of its regiments were formed into the District of the Frontier. History The army was created on October 12, 1862, composed of forces from the District of Southwest Missouri. General John M. Schofield was the army's first commander. Prior to this (from October 1–12, 1862) Schofield's field army was known as the Army of Southwestern Missouri. The Army of the Frontier consisted of three divisions at its largest. They were commanded respectively by James G. Blunt, James Totten, and Francis J. Herron. Units of the army (mostly Blunt's 1st Division) engaged in several small battles early in the war. The Battle of Prairie Grove in 1862 was the army's finest moment of the war. During the campaign General Schofield was in St. Louis due to illness, and General Blunt assumed temporary command of the army. Colonel Daniel Huston, Jr. temporarily replaced Totten in command of the 2nd Division. Both the 2nd and 3rd Divisions were then placed under the overall command of General Herron. Herron replaced Schofield as commander in March 1863. In May of that year the army's 2nd Division under William Vandever fought the Battle of Chalk Bluff against a Confederate raid under John S. Marmaduke. The army as a whole was dissolved on June 5, 1863, yet remnants were formed into "Herron's Division" and sent as reinforcements to the Siege of Vicksburg. Commanders General John M. Schofield (October 12, 1862 – November 20, 1862) General James G. Blunt (November 20, 1862 – December 29, 1862) General John M. Schofield (December 29, 1862 – March 30, 1863) General Francis J. Herron (March 30, 1863-5 June 1863) Major Battles Battle of Old Fort Wayne (Schofield) only Blunt's 1st Division was involved Battle of Prairie Grove (Blunt, field command) Battle of Chalk Bluff (Herron) only Vandever's 2nd Division was involved Siege of Vicksburg (Herron) as "Herron's Division, XIII Corps" District of the Frontier On June 6 the remaining units in Arkansas and the Indian Territory, formerly belonging to the Army of the Frontier, were organized into the District of the Frontier with General Blunt in command. The district was part of the Department of the Missouri and was composed of