Ok, everyone seems to really missed the point as to what Ron Paul was saying about the Civil War. Chris Matthews implied that being against Civil War means being for Slavery.
THE CIVIL WAR WASN'T ONLY ABOUT SLAVERY, this is Ron Pauls point, which is why he mentioned Slavery being on the decline. He posed the possibility of buying the slaves to show that if the war was about slavery there were better alternatives.
(if you think the US couldn't afford to buy the slaves, they had just formed a central bank to fund the war... so they could afford to spend for the war, they could afford to buy the slaves and release them)
The War was solely to prevent the States from from exercising their constitutional rights to secede which had more to deal more with Tariffs than slavery. Abe Lincoln like Bush suspended Habeas Corpus and abused opponent civil liberties to reach his ends.
If you condone this behavior from a president, then you cannot criticize Bush.
Remember, the winners write history.