David,
There was a Pvt Stephen Owens Co E, Ballentine's Regt Cav AKA 2d Ms. Partisan Rangers. Has 12 CWSR cards most show present, couple dismounted and detailed as teamster. Enlisted at Ripley,Ms. Aug 11, 1862.
Last card shows; 7th Regt.Ms. Cav. POW captured between Chickasaw Landing and Macon, Ga. between Mar 22 and Apr 20, 1865.

Ballentine's Regt. was formed from Independent and unattached companies operating in North Ms. in July 1862.
Mike