Please see my post 13. I did not raise the question to debate slavery, rather people's changing views of morality. Remember, both of the two amendments were offered within a few short years.
Lincoln knew that if four million slaves were released, they could then be able to help the progress in the North.
Booth wanted to kill Lincoln when Lincoln advocated going one step further after the war and proposed giving the slaves the right to vote.
Lincoln's proprosals progressed as his own views changed.