Recollecting what I think I was taught in private grade school, Lincoln wanted the slaves to move to and form a country in liberia.
Liberia already existed, from the early 1800s. But, yes, I think that was one of his ideas was to return them to Africa. At the time it probably seemed like a good idea. As it turned out, the post-war south was not a happy place for the former slaves, so an expanded Liberia, had it been backed by some investment, might not have been such a bad idea.