The American revolution was a war to separate the colonies from England so the war between the states would be the second American war of sucession.
I believe emancipation occured in Brazil and Puerto Rico in the 1870' and Cuba in the 1880's.
I believe the U S constitution reached a compromise only on the representation issue relating to the slave population. The issue of slavery itself was left to the states rather that the federal government.
I believe the sucession was about tariffs. The agricultural South either paid a tariff for imported manufactured goods or higher prices to Northern manufacturers. Effectively the Southern states were paying the cost of federal projects. Lincoln was a Whig, similar to today's crony capitalists, and wanted to greatly expand government financed projects.
Rather than humanitarian intent often ascribed to them many northerners simply wanted new states to be "white" only.
I believe had suceeding states been allowed to suceed slavery would have died a natural death for moral and economic reasons. In addition slaves escaping to the North would have no longer enforced the fugitive slave laws. Once slavery had ended the suceeding states very likely would have rejoined knowing the were free to leave as was tje original intent when the union began.