Plessy v. Ferguson ( 1896 ) was a United States Supreme Court case that ruled segregation was legal , as long as equal facilities were provided for both races . Plessy v. Ferguson , 163 U.S. 537 ( 1896 ) , is a landmark United States Supreme Court decision in the jurisprudence of the United States , upholding the constitutionality of state laws requiring racial segregation in private businesses ( particularly railroads ) , under the doctrine of `` separate but equal '' .