Lincoln did not invade the south because of slavery though. What he did was ignore the constitution. The Supreme Court said that Lincoln could not suspend habeas corpus without an act of congress. Lincoln ignored the Supreme Court and told the military to ignore the Supreme Court. After the war, the Supreme Court again said that it was illegal for the military to hold trials in areas where the civil courts could function. When the federal government decided to not put Jefferson Davis on trial for treason, they said they wanted to heal the division. A more believable argument is that they knew they would lose the case in the Supreme Court. Then what do you have? The Federal government invading a sovereign nation without an Act of War by the Congress, resulting in massive death, casualties, destruction of property, etc etc.
I feel some slight hope that least some of the states might actually try to regain what was taken from them illegally. The federal government was not supposed to meddle in the affairs of the states. The Constitution clearly lays out what the federal government can do, everything else is left up to the states and the people.
We can start with repraling the repeal of the Posse comitatus act that BUSH just signed!