Which doctrine was established by the Supreme Court decision in Plessy v. Ferguson?

The Supreme Court decision in Plessy v. Ferguson established the doctrine of "separate but equal." This ruling, decided in 1896, upheld the constitutionality of racial segregation laws for public facilities under the premise that if the separate facilities for African Americans and whites were equal, segregation did not violate the Equal Protection Clause of the Fourteenth Amendment. The court’s decision legitimized laws that scattered segregation throughout the United States, leading to widespread discrimination and the establishment of Jim Crow laws.

The ruling indicated that racial segregation could continue as long as the separate facilities were deemed equal, which in practice, they rarely were. This doctrine remained in effect until it was overturned by Brown v. Board of Education in 1954, which found that separate educational facilities are inherently unequal, thus paving the way for the civil rights movement.