What made racism?

Well slavery is the closest. Some people still think whites want them to be slaves but some whites are mad at the black people because they think they're mad about it. The most accurate reason though is they think they act different. It's not really any certain race that acts different though. Some people who meet another race who acts different automatically assume that they all act like that so they go with that and treat them different. They usually cover that up with an excuse of "They just don't go together".