There was no revolt by the Southern states, they wanted to peacefully leave what had become an untenable situation with the federal government in Washington.
There was however an unconstitutional invasion of the Southern states by federal troops that resulted in the loss of thousand of lives on both sides. Lincoln's War of Northern Aggression is looked at differently in the South.
...the fact remains that the Confederate flag is the banner of a vanquished enemy.
Vanquished? Yes. Enemy? Well that depends on which side of the Mason-Dixon you're standing on.
The offended folks in Wisconsin are well north of that line.