It is likely that Steven Jarrell was not in the 25th Texas Cavalry when it was first raised in Texas at Camp Nelson under Col. Clayton Gillespie. After being detached from Walker's Infantry Division, the 25th Texas Cavalry (dismounted) was one of the regiments that was captured intact at Arkasas Post. The enlisted men of the regiment were not exchanged and they sat out the war in the Douglas Prison Camp near Chicago. However, "captured intact" does not necessarily mean every soldier was captured. He may have been away from the area when the regiment was captured. Men were sent to forage or were not with their unit for some reason.

For example, my great grandfather Pvt. Joshua D. Coffee and 24 soldiers of Capt. John Henry Damron's "spy" company of the 1st Texas Cavalry, Arizona Brigade, were on detached picket/patrol duty in Indian Territory when the 1st Texas Cavalry Regiment left north Texas. Not meeting roll call and their whereabouts unknown, all 25 soldiers were declared deserters. Six months later the 25 men that were declared deserters were reassigned to the Brush Battalion of Col. James G. Bourland's Border Regiment, C.S. Army.

Steven Jarrell may have enlisted in or was transferred to the 25th Texas Cavalry when the regiment was reorganized under Col. James Deshler and was sent east of the Mississippi River. Since Steven Jarrell settled in Louisiana after the war, he may have enlisted in a Louisiana regiment when the war began and was transferred to the 25th Texas Cavalry. That is probably what happened if Steven Jarrell lived in Louisiana before the war.