drive over to savannah visit tybee island half way between savannah and brunswick is an old rice plantation.that drive should take about 1 1/2 hours at brunswick there is st.simons island nice beaches about an hour south of savannah.While in savannah dine at the pirates house resturant.It was written about in robert lewis stevensons treasure island as the savannah inn--loads of history.
If you are driving from Atlanta, you can circle off of I-20 at Crawfordville and visit the Alexander Stephens home and museum (VP of the Confederacy). http://gastateparks.org/info/ahsteph/
25 miles northeast of Crawfordville is Washington, Ga, which is full of historic homes including the Robert Toombs house.
Savannah would be a good choice for a side trip. The historic area is fairly compact and good for walking. A side trip would take you out to Fort Pulaski. Further down the coast you get to Darien and St. Simons Island (historic sites) or Jekyll Island (beaches).
Going the opposite direction from Augusta, one of the best battlefield sites in Georgia is just outside of Atlanta at Kennesaw Mountain.