Which Supreme Court decision upheld the constitutionality of racial segregation under the "separate but equal" doctrine?

The selection of Plessy v. Ferguson is justified because this landmark Supreme Court decision established the legal precedent for racial segregation in public facilities under the doctrine of "separate but equal." The case arose in 1896 when Homer Plessy, an African American man, challenged Louisiana's segregation laws after being arrested for sitting in a "whites-only" railroad car. The Supreme Court's ruling asserted that as long as the segregated facilities were equal in quality, segregation did not violate the Equal Protection Clause of the Fourteenth Amendment. This decision provided a legal framework that allowed racial segregation to persist for decades until it was eventually challenged and overturned by future cases, most notably Brown v. Board of Education in 1954, which declared that "separate but equal" was inherently unequal in the context of public education.