Jim Crow or jim crow 
(jĭm krō)
(jĭm krō)n.
The systematic practice of discriminating against and segregating black people, especially as practiced in the American South from the end of Reconstruction to the mid-1900s.
adj.
1. Upholding or practicing discrimination against and segregation of black people: Jim Crow laws; a Jim Crow town.
2. Reserved or set aside for a racial or ethnic group that is to be discriminated against: "I told them I wouldn't take a Jim Crow job" (Ralph Bunche).
[From obsolete Jim Crow, derogatory name for a black person, ultimately from the title of a 19th-century minstrel song.]
Jim-Crowism (-krōĭz′əm) n.