It was pretty clear that the end of slavery was coming even had the war not been fought. The industrial age was upon us and the sharecropper system that did happen would have happened anyway. You may not agree with that but that's my take on it.
Not too sure about the 40 acres and a mule thing though. Unless land was given in a grant for former military service or as part of the early immigration deals, most whites had to buy or rent land. That probably would have been the case for former slaves had the Feds not passed out land they stole. One point many people fail to understand is that the real cause of ill feelings in the South was not the reason for war, not caused by the surrender. It was the use of Martial Law. The restriction of the freedom of assembly right and the deluge of carpetbaggers who flaunted the surrender in their faces. Don't think for one minute that any Southerner, not just Black ones, has not felt the sting of prejudice. We are still getting the needles stuck to us on a regular basis.