Check out - Popular Art and Racism: Embedding Racial Stereotypes in the American Mindset--Jim Crow and Popular Culture by Ronald Davis

http://www.jimcrowhistory.org/resources/lessonplans/hs_es_popular_culture.htm

"The onset of Jim Crow laws and customs rested upon the racist characterization of black people as culturally, personally, and biologically inferior. This image functioned as the racial bedrock of American popular culture after 1900, especially manifested in minstrel shows, the vaudeville theatre, songs and music, film and radio, and commercial advertising. So pervasive was the racial demeaning of black people, and so accepted was it by white Americans throughout the nation, that blackness became synonymous with silliness, deprivation, and ignorance. Most white Americans believed that all Africans and their descendants were racially inferior to whites, and that their common inferiority tied them together wherever they might live in the modern world.

In America, black people were portrayed as inferior almost from the time of their enslavement in the colonies in the 1620s. This racial characterization enabled white masters to justify slavery as something positive. Using racial stereotypes to justify the enslavement of blacks was especially pronounced after 1830 as white Southerners defended slavery against attacks by northern abolitionists."

History tells the tale...