In October 1864, Col. Reuben R. Brown was placed command of the 35th Texas Cavalry Regiment, Brig.Gen. Henry E.McCulloch's 8th Texas Cavalry Brigade, Northern Sub-District of Texas.

Col. R.R. Brown's 35th Texas Cavalry Regiment was also known as "Brown's Regiment" by December 1864. Some regular Confederate army regiments and county brigade units of Texas State Troops remained in the Northern Sub-District of Texas for defense of the frontier against Indians, Kansas redlegs, outlaws, deserters, and Union sympathsizers.