If you could change an important event in the past 1,000 years, what would it be?

If i could change an event from the past 1,000 years, I would go and prevent slavery from happening. My reason is because too many people had to suffer for things that they didn't do. Usually African Americans were the ones who were affected by slavery. They were wrongfully accused for many things, and were treated horribly. Nobody really cared for them, and never thought of them as regular people.

To change their horrible past, I would go back in time, and prevent everything from happening. For example, i would have everyone get good jobs that are safe, and choose people that are right for them. Since the reason that jobs were hard to find for slaves, this opportunity that i would give them is a chance to start a new beginning. They wouldn't have to suffer from be treated like trash, and they would be paid to support their families.