Who or what started the black stereotype? Was it a group or an individual? Why was it an African Americans? Did someone great 1000x grandfather offend someone once?

How did it even make it into science community? Like African American's have small minds, can't comprehend stuff the way whites can....blah blah blah..Have a hard time believing that one day a society or country and said lets hate group B over here because they are different. How in god's green earth is that crap still around today within the advancement of the world? Sorry trying to stay on topic and not cuss...thanks for all information.