You raise an interesting point with the slavery. I'm not sure if it's such a good analogy, but saying it is, Abraham Lincoln did try to free the slaves. There will be people, probably a lot of people, who will feel threatened by them, just like now there are people being afraid of robots taking their jobs (which is another interesting debate), but things will still change gradually, as robots become smart enough, "lovable" enough, and human-like enough, and some people will even want to marry them.

A few years ago I was reading sort of a joke, that by 2050, Massachusetts will be the first state that will allow human-to-robot marriages.

There's already this:

http://www.youtube.com/watch?v=9q4qwLknKag