The Frontier Organization represented the final modification of frontier defense in Texas during the Civil War. In 1863 Governor Pendleton Murrah and the legislature proposed to transfer the state-supported Frontier Regiment to Confederate service. Such a move would have relieved the state of a financial burden, but the regiment would then have been under Confederate control, subject to removal from the frontier at the discretion of Confederate commanders. Concern for the protection of the frontier played a major role in deliberations of the Tenth Legislature in late 1863, as state officials hesitated to transfer the Frontier Regiment to the Confederacy without assuring the best protection possible for the frontier counties. The resulting law, which established the Frontier Organization and transferred the Frontier Regiment, passed the legislature on December 15, 1863.
The law declared that all persons liable for military service who were actual residents of the frontier counties of Texas were to be enrolled into companies of from twenty-five to sixty-five men. The act defined the frontier line and the fifty-nine organized frontier counties of Texas; it also instructed Governor Murrah to divide the designated counties into three districts and to appoint a suitable man with the rank of major of cavalry to take charge of the organization of mounted companies within the district. The major of each district was to require that one-fourth of his men, on a rotation basis, be in service at any one time. In January 1864 Murrah appointed three men to take command of the frontier districts. William Quayle commanded the First Frontier District, headquartered in Decatur; George Bernard Erath commanded the Second Frontier District, headquartered in Gatesville; and James M. Hunter commanded the Third Frontier District, headquartered in Fredericksburg. Nearly 4,000 men were on the rolls of the organization by the time of the Frontier Regiment's transfer on March 1, 1864.
James Webb Throckmorton replaced Quayle in December 1864 as commander of the First Frontier District. In January 1865 John Henry Brown replaced Hunter in the Third Frontier District. Coordinating military affairs in the Second and Third Military districts, however, was John D. McAdoo, brigadier general of state troops, who took command in June 1864, initially to quell unrest over Hunter's administration of the district. McAdoo remained in direct command of the Third District until Brown's arrival and later coordinated activities of the Second and Third districts until the end of the war.
Companies in the Frontier Organization normally averaged between fifty and fifty-five men in strength, usually with about fifteen men per squad for patrol duty. The length of service at any one time varied according to the task, presence of the enemy, and availability of supplies, but most squads on patrol duty expected to remain out for about ten days at a time. The Frontier Organization not only provided protection against Indian incursions but also enforced Confederate conscription, rounded up deserters, and provided protection to settlers from renegades and bandits. The Frontier Organization assumed chief responsibility for the protection of the Texas frontier from March 1864 until several months after the end of the war. Its engagements included the Ellison Springs Indian Fight.