Lincoln would have the very difficult task of handling Reconstruction. Whatever happened, his decisions would be unpopular with many people. That and his being wounded instead of killed would make him less of a secular martyr, so history might not remember him as well. OTOH, I think Lincoln was skilled enough he could lay a far better basis for protecting the freedmen and southern white Unionists, though doing better than Andrew Johnson is setting a pretty low bar. Couple that with probably Grant succession and civil rights in the south would be much more firmly established than in OTL. A version of Jim Crow might still be implemented, but it would probably be less awful than in OTL.