Well, anti-Southern bigotry is one of the last "safe" bigotries, and it's very hard to get liberals to listen to any reason or fact. For example, these folks obviously don't know that in early 1865, the Confederacy began the process of ending slavery via recruitment of slaves to serve in the army in exchange for their freedom.
The bill that authorized this was bitterly, heatedly debated in the Confederate Congress, precisely because everybody knew that if it had time to play out, it would spell the end of Southern slavery. Well, the bill passed and the Confederacy began to process of offering freedom to slaves who would join the army, and some did begin to join. But, the process never had a chance to play out because the war ended a few weeks later.
The bill that authorized this was bitterly, heatedly debated in the Confederate Congress, precisely because everybody knew that if it had time to play out, it would spell the end of Southern slavery. Well, the bill passed and the Confederacy began to process of offering freedom to slaves who would join the army, and some did begin to join. But, the process never had a chance to play out because the war ended a few weeks later.