Hi Dwight:
Was the 15th Texas Cavalry Regiment still in Little Rock in June 1862? A regimental history states that by May 1862, the regiment was in Little Rock, Arkansas. My grandfather's brother, Joseph B. Ables enlisted in Company H in Hunt County, TX in April 1862 and died in hospital in Arkansas in June 1862. He probably enlisted the same time your ancestor did when the regiment passed through Hunt County on its way to Clarksville.
Thanks
Ernie Abel