I think most people when you say slavery tend to see a group of anonymous people pulling cotton sacks in great plantation fields, and that is largely true.
If you go back to before mankind came out of the cave, there was hatred.
Racism and hatred are synonymous.
Either you deal with what is the reality, or you can be sure that the reality is going to deal with you.
You have to deal with the fact that your life is your life.
Unless we learn from history, we are destined to repeat it. This is no longer merely an academic exercise, but may contain our worlds fate and our destiny.