up South, n. — Green’s Dictionary of Slang

up South n.

[the implication is that racism and prejudice is just as widespread as it is ‘down South’]

(US black) the Northern states.

1972		O. Hawkins Ghetto Sketches 248: Georgia . . . where I learned where down south was, I already knew where up south was.
1996		Eble Sl. and Sociability 82: Many terms that originated among African Americans remain for the most part in that community, like [...] Up-South ‘the North.’.