yes/no Tough question/easy question.
I think the 40 acres and a mule plan initated by Sherman would have been just compensation, and could be siezed from the traitors who took up arms against the United States of America. It might have also been politically difficult in trying to heal the wounds of the war, but I think it would have at least been just at the time.
But retroactive action, no, the people who were enslaved are long gone, as are those who enslaved them. I think we should admit the ugly things in our nation's past, but that doesn't mean we are personally responsible for them today.
I wonder how good of a slave Philip would make. I figure there's more than a few folks around who could easily best him in personal combat under his "might makes right" ideology and make him their bi*ch.