During the Civil War Charleston and Atlanta were burned to the ground by the Yankees, but Savannah was spared. They were occupied for a time by the North, which is probably why they weren't burned. There are a lot of homes/businesses from the 1700's/early 1800's left, and most have been very well maintained. It is a very beautiful and interesting place.
Most of River Street is bars/grills, so there isn't much sightseeing to do there, but do take a riverboat ride, it's very informative. The carriage rides are interesting, and save a lot of walking, but they are very crowded accomodations, and you don't slow down or stop to see anything. It's true that Savannah was a pretty wild town in it's day, but I think mainly because it was a main seaport(You Know How Them Sailors Are!!), and it is the oldest city in Georgia. It was originally colonized by debtors, brought here from the English jails. That was done because you had the English in the North and the French in the South, and they were constantly fighting over the territory. The English considered the debtors expendable, and easily replaced since the jails were full of them, so they placed them in Savannah as a sort of Buffer Zone to slow down the French advancing northward. A large part of the affluent Savannah society came from New York, New Jersey and Pennsylvania, generally military persons who were there to protect the territory in the early 1700's. It is truly a wonderful visit if you are interested in architecture and history. It is hot, and there is a lot of walking involved if you want to see things at a leisurly pace. I would be a little wary of some of the antique shops, I did see an awful lot of reproductions, some of the higher priced "high class" restaurants were a bust(one on 37th/Drayton for sure), and the closer you get to the historic district the higher the room rates, but there is plenty of public parking that is very affordable, so we took a room at the far southern end at I-95.
All in all, it is a very nice vacation.