Final answer:
The Supreme Court case that established 'separate but equal' was Plessy v. Ferguson (1896), but this decision was later overturned in the landmark case Brown v. Board of Education (1954).
Step-by-step explanation:
The Supreme Court case that established the principle of 'separate but equal' was Plessy v. Ferguson (1896).This landmark decision upheld racial segregation policies for public facilities under the doctrine that such facilities could be separate as long as they were purportedly equal. However, the Brown v. Board of Education (1954) case overruled this precedent, determining that separate educational facilities are inherently unequal, thus ending de jure segregation in public schools in the United States.
In this case, the Supreme Court upheld racial segregation by ruling that segregated facilities that were supposedly equal in quality did not violate the Fourteenth Amendment's guarantee of equal protection under the law. However, this decision was later overturned in the landmark case Brown v. Board of Education (1954), in which the Supreme Court declared that separate educational facilities were inherently unequal.