Hello Judith,
The next time I'm at the NARA in DC I'll check on those names and see what prison they were held at. As you probaby know DeVall's Bluff was NOT a prison itself but rather a point where the soldiers were released from the Army if you will.
Your description could fit numerous prisons during the War however two come to my mind, Andersonville and Camp Cahaba. It may be a few months before I get back to DC as I was just there last week.
I will post my findings on this site when I find them.