Your premise is that b/c slavery is considered wrong, abortion is considered right. DUH... it makes absolutely no sense.
Slavery has existed throughout man's history. You might even say it's human nature. African-Americans, it's been noted, suffered the worst slavery in the history of man b/c they had no rights. Most countries from time immemorial sanctioned excessive whipping, torturing, and starvation. But in America, slaves were pretty much to the whim of their masters. It was a horrible time in America, and I think you should be more sensitive to Americans who are dealing with the legacy of that era.
Babies in the womb are not to be killed off like you're stomping on a bug. They are living people who just haven't grown up yet. It's insane to speculate that one day abortion will be considered "okay" or "right". It is never okay to cold-blooded kill someone.
I truly hope you get out of the moral black pit you are in. You honestly need prayer, and I, for one, will pray for you. You are represented of many sick people in our country, so it's not just you. It's scary to think some people have no feelings for fetuses, babies, and children.