One of the bloodiest battles of the Civil War was conducted at Shiloh, and almost every junior high school child had a field trip to visit Pickwick Dam.  There is so much to see, between the Civil War monuments and the engineering feats with Pickwick Dam.  

Here is a link to the Shiloh National Military Park showing its list of programs scheduled throughout the year.  You will not run out of things to do if you want to learn about the rift that tore this nation apart.

National Geographic has a detailed spread with a ton of old photographs and recent ones of reenactments: