James -- William McDaniel Reaves is my great grandfather and I have been doing plenty of research on his service record, along with that of his three brothers who also served in the war. Indeed, Mac served in the 21st Alabama and was captured at the Battle of Mobile when Ft Gaines was surrendered in August 1864. He was taken first to New Orleans and then moved to Ship Island where he was a POW until Jan 1865. He was released, re-joined his unit and subsequently surrendered with his unit in April 1865.

Somehow we must be related! If interested, contact me and we can find some time to talk. Take care.