If interested in the War Between the States, the Cyclorama in Atlanta's Grant Park and the Museum of Southern Locomotive History(or something like that) in Marietta/Kennesaw. The museum, I believe, houses the locomotive "General" of Great Locomotive Chase fame might be of interest, or the Kennesaw Mtn Battlefield. The other locomotive, "TEXAS", from the chase, used to be at the Cyclorama - don't know if it's still there or not.
If you had the foresight to take shooting gear with you to Marietta, there's a silhouette shoot up in Baldwin GA this weekend hosted by Blue Ridge Mtn Men.
Here's a link to a list of other museums that pertain to things like the Cherokee culture in the area:
http://roadsidegeorgia.com/site/kcwm.html (you'll have to scroll down a bit).
Enjoy. SCL