Last weekend they held a Civil War re-enactment at a farm a couple miles from my apartment. It was a good show, and they did a decent job with the historical accuracy. Even the snack vendors wore period clothing and sold traditional food.
There were also people selling books with titles like "Why the South was Right". I never actually heard the phrase 'The War of Northern Aggression' but the sentiment was clearly there.
This attitude is not as ridiculous as it might appear. Fighting a war to guarantee human rights for a large number of people is clearly justified, but fighting a war to preserve a political entity is not. The historical evidence on Lincoln's actual motivations is mixed.