Which Supreme Court case established the "separate but equal" doctrine?

The Supreme Court case that established the "separate but equal" doctrine is Plessy v. Ferguson. Decided in 1896, this landmark ruling upheld state laws that mandated racial segregation in public facilities, positing that as long as the separate facilities for the separate races were equal, segregation did not violate the 14th Amendment's Equal Protection Clause. This decision provided a legal justification for the segregation laws that would permeate the United States for decades, essentially sanctioning racial discrimination and leading to a multitude of Jim Crow laws across the South.

In contrast, Brown v. Board of Education, decided in 1954, later overturned Plessy v. Ferguson, declaring that separate educational facilities are inherently unequal and thus unconstitutional. Roe v. Wade and Miranda v. Arizona deal with different legal principles—one regarding a woman's right to privacy in making medical decisions and the other about the rights of individuals in police custody, respectively. Hence, Plessy v. Ferguson is definitive for its establishment of the "separate but equal" doctrine, shaping the legal landscape of civil rights prior to the Civil Rights Movement.