The Jim Crow laws made segregation illegal.
Jim Crow laws . De jure segregation existed mainly in the Southern states , while Northern segregation was generally de facto -- patterns of housing segregation enforced by private covenants , bank lending practices , and job discrimination , including discriminatory labor union practices . Jim Crow laws -- sometimes , as in Florida , part of state constitutions -- mandated the segregation of public schools , public places , and public transportation , and the segregation of restrooms , restaurants , and drinking fountains for whites and blacks .