Everything I've ever read argues that the new forms of entertainment (professional sports, vaudeville, Wild West Shows, etc) were a very democratizing force in Gilded Age America.
The textbooks I've taught from say that people of all classes attended these kinds of entertainment and that they were expected to act in middle class ways.
So I guess in that sense I'd say that the rise of these entertainments did not really reflect social divisions but did shape them in a sense. They shaped society by working to do away with social divisions and provide more of a mass culture.
I would guess that African Americans were least affected, but I have not read that anywhere.