Wow! I just recently looked at this picture. From what I've read, it is a camp of Alabama troops on Bayou Grande. Now Bayou Grande is on the back side of NAS Pensacola so my hopes it was in what is now Navy Point (where I grew up) sort of got dashed. Will try to find it again and see if there's any other id on them. JD Edwards took the majority of photo's here at that time. There is a booklet with those from the Civil War available.
I don't believe this is a home guard group. This was in the very beginning when they first arrived and the 'dress code' was a bit loose. Quite a few of the photo's of the Confederates then show the dress quite varied.