Fort Washita was located on the east side of the Washita River in Indian Territory (Oklahoma), about thirty miles upstream from the rivers confluence with the Red River at Coffee's Trading Post, near Preston, Texas.

Col.Almarine Alexander's 34th Texas Cavalry (2nd Partisan Rangers) was raised during the winter of 1861 and 1862 in north Texas, Fort Washita.It was accepted into Confederate service at Tahlequah, I.T. with some Indian regiments under Col. Douglas Cooper in the spring of 1862. In the fall of 1862, the 34th Texas "Plowhorse Cavalry" saw action at Shirley's Ford and Newtonia Missouri before being driven back into Arkansas. After the battle of Newtonia, the regiment weakened by sickness, poor morale, and desertions was dismounted. In January 1863, the 34th Texas Dismounted Cavalry was combined with the Col. Joseph Warren Speight's 15th Texas Infantry.In th espring of 1863, the 15th Texas Infantry and 34th Texas Dismounted Cavalry was placed in Brig. Gen. Camille de Poliganc's Brigade and saw action in Arkansas and Louisiana. In May 1863 Col. Alexander resigned due to poor health and Col. William M. Bush took command. On June 2,1865, Poliganc's Brigade and Walker's Division was disbanded at Camp Groce near Hempstead Texas.