Why are people in Maycomb prejudiced against Negroes in To kill a Mockingbird?

Racism has always been around. The American south, in particular, has been a hotbed of racism against the Negro population. One can a safely argue that it still is. Much of this culture goes back to the slavery system and the American civil war. The south lost badly and for some reason the hatred never quite went away. In the novel, blacks and whites were segregated. That is very few mixed on a personal level.The old race relations of the south were firmly entrenched in Scout's world. Being white meant a physical and emotional separation from the black population. Scout and Jem at least got to experience a housekeeper /mother-figure in Calpurnia. Years of ignorance, hatred, social conditioning and rawness from the Civil War were, and apparently still are, tough to change.