Lincoln was evolving on the equality issue and was head and shoulders far more advanced the Lee or Davis. Sherman for all of his faults freed slaves especially by shortening the war by his March through Georgia.Just as not all former yankees were in favor of racial equality [e.g. Lincoln, Sherman]
Also @RobertP ,From Butlers autobiography:
"If these black soldiers of ours go back to the South I am afraid that they will be but little better off with their masters than they were before, and yet they will be free men. I fear a race war, and it will be at least a guerilla war because we have taught these men how to fight. All the arms of the South are now in the hands of their troops, and when we capture them we of course will take their arms. There are plenty of men in the North who will furnish the negroes with arms if there is any oppression of them by their late masters.
"I wish you would carefully examine the question and give me your views upon it and go into the figures, as you did before in some degree, so as to show whether the negroes can be exported. I wish also you would give me any views that you have as to how to deal with the negro troops after the war. Some people think that we shall have trouble with our white troops after they are disbanded, but I don't anticipate anything of that sort, for all the intelligent men among them were good citizens or they would not have been good soldiers. But the question of the colored troops troubles me exceedingly. I wish you would do this as soon as you can, because I am to go down to City Point shortly and may meet negotiators for peace there, and I may want to talk this matter over with General Grant if he isn't too busy."
Butler's Book, pg. 903
The above quote doesn't mean Lincoln approved a Colonization scheme only he was asked to give his thoughts on it.