Organized as the Arizona Battalion by Lt. Col. John Robert Baylor, Confederate governor of the Arizona Territory, the Arizona Scouts mustered as Confederate mounted militia for a term of twelve months. Arizona settlers that joined the battalion were frequently identified as cowboys rather than soldiers. The Mesilla Times of January 15, 1862, described them as "well officered, but badly clothed, badly fed, and badly armed...composed almost entirely of cavalry." George M. Frazer, a Mesilla businessman, had organized the first company, the Arizona Rangers, in May 1861 to protect local citizens and retaliate against Apache outrages. Additional companies included the Arizona Guards, the San Elizario Spy Company, and a company of scouts organized as Company A by Sherod Hunter of Frazer's command. The Arizona Battalion acted as scouts for Colonel Baylor and later for Brig. Gen. Henry H. Sibley's invasion force. On February 9, 1862, Captain Hunter marched part of the battalion to Tucson with instructions from Baylor to maintain law and order throughout the area, establish friendly relations with the Pima and Papago Indians, recruit Southern sympathizers, and monitor the movement of Union forces from California. While stationed around Tucson, a detachment of Hunter's command participated in the westernmost battle of the Civil War at Picacho Pass. On April 15, they encountered an advance guard of the California Column and in a brief skirmish killed two Federals and wounded four, while losing three of their unit as prisoners of war. Captain Hunter began his withdrawal from Tucson in mid-May to rendezvous with General Sibley's retreating army at Fort Bliss in El Paso. The Arizona volunteers accompanied the Confederate Army back to Texas with many, such as George Frazer, bringing their families to resettle in safety.
Establishing a camp in San Antonio, Colonel Baylor began to recruit for an Arizona Brigade that would return to fight in the southwestern territories. The Arizona Battalion was to form the first of five battalions in Baylor's proposed brigade. When Baylor lost command of the brigade because his controversial policies toward the Apaches in Arizona became public, Maj. Gen. John Magruder reorganized the small incomplete battalions into three regiments. In February 1863 the Arizona Battalion was attached to the Third Texas Cavalry, Arizona Brigade. By this time, many of the original members had joined other companies, and the battalion's ranks had become so thin that they numbered little more than a company. When George Frazer became regimental major for the Third Texas Cavalry, Arizona Brigade, Capt. James H. Tevis, a former Butterfield Overland Mail agent, took command of the volunteers then known as the Arizona Scouts. The Scouts accompanied the Third Texas Cavalry, Arizona Brigade, into Louisiana in April 1863 to support Gen. Richard Taylor's army. During the rest of 1863, they participated in battles at Brashear City, Fort Butler, and at Stirling's Plantation where Major Frazer commanded the regiment. In December they returned to Texas and made camp at Galveston to assist in the defense against a Union expedition advancing up the coast from Brownsville. The Arizona Scouts served in the advance guard of the Galveston defenses, known as Saufley's Scouting Battalion. In March 1864 they became part of the force of Texas cavalry sent to Louisiana for the Red River campaign. The Arizona Scouts fought in the battles of Mansfield, Pleasant Hill and Yellow Bayou. On May 1, 1864, they were part of a detachment that pursued, captured, and burned the Union transport Emma. During this period, a few of the Scouts accompanied Maj. Sherod Hunter to Eagle Pass, Texas, for the purpose of raising a regiment to harass Union troops in the Arizona Territory. On September 1, 1864, the rest of the company marched to Arkansas with the Texas cavalry and returned to Texas in December. They remained in the Houston area until the surrender of the Trans-Mississippi Department on May 26, 1865. Captain Tevis recalled, "My command was the last to be mustered out at Hempstead, Texas. I proceeded to San Antonio, and my men, some fifteen of them, scattered in all directions and only three of them ever arrived at Mesilla." Tevis lived in St. Louis and Austin and then returned to the Arizona Territory in 1880. The Arizona Scouts' first commander, George Frazer, moved his family to Fort Stockton and later served as the first judge of Pecos County.