 The United States Supreme Court, made up almost entirely of Northerners, upheld the constitutionality of those state laws that required racial segregation in public facilities in its 1896 decision "Plessy v. Ferguson", legitimizing them through the "separate but equal" doctrine.Segregation, which began with slavery, continued with Jim Crow laws, with signs used to show blacks where they could legally walk, talk, drink, rest, or eat.For those places that were racially mixed, non-whites had to wait until all white customers were served first.