Unless I missed something the service record only includes a record of capture at Fort Gaines, not Blakely. Most men captured at Blakely spent a brief time at Ship Island enroute to New Orleans. From that point they were taken to Vicksburg MS and paroled along the Big Black River. I don't see that record for this soldier.

Also, the remnant of the 21st Alabama Regiment was at Spanish Fort, not Blakley. You can check Art's book or John Kent Folmar, From That Terrible Field: Civil War Letters of James M. Williams, Twenty-First Alabama Infantry Volunters , p. 159. The men were evacuated during the night before the assault on Blakely.