I just finished watching The World, The Flesh, and The Devil which starred Harry Belafonte as a black man struggling with racial in a post apocalyptic world. I don’t want to go over the full synopsis since you can get that here and here. Overall it has the feel of The Omega Man and I am Legend – though it predates The Omega Man by twenty years (I Am Legend by over fifty). The difference though is this movie has no zombie like creatures of any sorts.
It deals with the racial issues of the time combined with dealing with the loneliness of living in such a world. If you wanted to look at the actual issues of loneliness and society at the end of the world I can say you should defintely hunt this movie down and watch it.