 At the same time resentment of these gains by many whites resulted in an unprecedented campaign of violence which was waged by local chapters of the Ku Klux Klan, and in the 1870s it was waged by paramilitary groups like the Red Shirts and White League.In 1896, the Supreme Court ruled in "Plessy v. Ferguson", a landmark upholding "separate but equal" racial segregation as constitutional.It was a devastating setback for civil rights, as the legal, social, and political status of the black population reached a nadir.