Of interest, while my ggrandpops was a Confederate manning the rifle pits along a Mississippi River Marine Battery, my wife's ggrandpa was a Union sailor, and had been Captain of the After Guard on the gunsboat, Cinncinatti, sister ship to the Cairo, being invalided off shortly before she was sunk by the Vicksburg marine batteries.

Captain of the Afterguard would be equivalent to Petty Officer in charge of the stern area of the ship.

So, not only was it a war between brothers, one can also say a war between great grandfathers!

Hope you'll have better luck on your next visit. Chickamauga in my mind, has nothing of the charm you'll find at Vicksburg and vicinity.