I wanted to update my email address in case anyone runs across this post and my previous one and wants to contact me. My broad assumption is that there were several local companies formed and assigned to Savannah. Georgia was very concerned about invasion and very much wanted to guard his coastline, so coastal artillery and protection was apparently a major push. It appears that these various companies were formed into this unit in 1864. They then apparently joined Hardee (and later Johnston) on the long march through South and North Carolina trying to block Sherman from joining forces with Grant. This unit appears to have been at Bentonville, but I don't think they were much engaged in the battle. They finally surrendered with Johnston. Still interested in developing more info on this obscure unit.