What was the Supreme Court's ruling in Plessy v. Ferguson regarding segregation?

The Supreme Court's ruling in Plessy v. Ferguson established the doctrine of "separate but equal," which effectively upheld racial segregation laws as long as the separate facilities for the races were considered equal in quality. This ruling stemmed from a case involving Homer Plessy, who was of mixed race and challenged Louisiana's segregation laws after being arrested for sitting in a whites-only train car.

The Court's decision, delivered in 1896, argued that the state law did not violate the Equal Protection Clause of the Fourteenth Amendment. This landmark ruling provided a legal basis for racial segregation across many public facilities, legitimizing discriminatory practices that persisted for decades until they were challenged and ultimately overturned by later cases, such as Brown v. Board of Education in 1954.

The other choices reflect differing outcomes or issues that were not decided in this case. For example, it did not find segregation unconstitutional, did not establish federal regulations for public transportation, nor did it mandate immediate desegregation in schools, which were issues addressed in later legal contexts.