Answer:
Genocides still happen because there are people in this world that think that problems can be solved through violence. We can help stop genocides by re-enforcing laws and teach others about this subject.
As an intimidation tactic.
Think about it:
If black kids are beaten up for going to school, will they even want to go to school?
If a black man was going to go vote, but the night before, the local sheriff came by and told him he'd "cause trouble" for him and his family if he votes, will he still want to vote?
Basically, violence was used to scare black people into obeying.
One defining characteristic of the Era of Good Feelings was the industry. People began to work in factories as well as produce steamboats, engines, etc.