There were a lot of factors, mostly being based around education and emancipation, but also religion. People either educated themselves and started realizing how wrong slavery is and that African Americans aren't actually different, but rather the same as us, or they were motivated by religious beliefs that all people were created by god to be equals and that slavery is against god.
It won’t let me put my answer in
Answer:
Dang bro you down bad... smhh
Belief that America will grow bigger and bigger
The leader is Genghis Khan