In the landmark case Plessy v. Ferguson, the Supreme Court of the United States upheld the constitutionality of "separate but equal" public facilities. The Supreme Court’s ruling allowed for legal segregation on the basis of race in the United States for almost six decades until the decision was overturned in Brown v. Board of Education on May 17, 1954.

https://www.britannica.com/event/Plessy-v-Ferguson-1896