Black History Month: Why Did Slavery Happen?

I spend a lot of my time talking with my daughter. She is still young enough to provide a fresh perspective on life that is free from the framing of a news outlet or a political agenda.

So yesterday when we got into a conversation about slavery --- presumably because her school is celebrating Black History Month, she asked me, "Why did they do that? Why were those people so mean to them just because they didn't have the same skin as they did?"

Her question was so impassioned it sounded more like a plea --- Daddy, please tell me how this could have happened?