Nashville, then Memphis, then Vicksburg

I am going to echo what Executive said. Being a Civil War Junkie I have' been to many battleground sites around the South but Vicksburg is by far my favorite, allow as many hours as possible for the driving tour, definetly go inside the visitor center and see the displays and don't miss the resurrected Union gunboat display, fascinating.

As far as the Ameristar it is convenient but it is the only campground I have ever had to move twice before I found a level enough site and it wasn't that great. There are some level sites, scout before you check in and tell them what site you want.