"After the war Robert E. Lee also wrote, "The best men in the South have long desired to do away with the institution [of slavery], and were quite willing to see it abolished. But with them in relation to this subject is a serious question today. Unless some humane course, based on wisdom and Christian principles, is adopted, you do them great injustice in setting them free."
This was a bit of a cop out. While I believe the South was evolving in such a way that would eventually be rid of slavery, the above was an excuse borne of fear of economic disaster. They felt they could not afford to get rid of slavery so the next best solution was to treat them as well as possible and to free a few slaves as a reward when the owner can afford to do so.
What about the slaves in the Union, who were excluded for the Emancipation Proclamation of Lincoln?
That ommission was by design. Lincoln freed no slaves under Union control.