Wrong thread, this definitely belongs in the pre-1900 arena.
Why?:
1) The Confederacy wins early on, but is then forced by Britain, France and the US to emancipate or lose the three greatest cotton markets in the world, or...
2) The Confederacy wins after freedmen enlistment begins. When the CS Congress authorizes the manumission of slaves to serve under the Stars and Bars, slavery is dead in the South. That realization is the main reason why it wasn't passed until early 1865, eventhough the call to enlist blacks began in 1862-3...