I know they supported it before the war (Edit: he'll they went to war for it), and argued it wasn't THAT bad afterwards for a long time. However, was the war ever seen on Biblical terms - perhaps that the destruction of the South by the perceived cruelties of Sherman's March was a punishment from God for the sin of slavery? Did they ever admit to slavery being a moral wrong, after the war, basically, even if they viewed slavemasters as good people and abolitionists as bad?
After the Civil War, the South re-invented the Confederate cause to be about states' right and downplayed slavery and its inherent cruelties.
Do you have a source for this?