Which landmark Supreme Court case established the principle of "separate but equal"?

The principle of "separate but equal" was established in the Supreme Court case Plessy v. Ferguson. This ruling, decided in 1896, upheld state laws that mandated racial segregation in public facilities, asserting that as long as the separate facilities for African Americans and whites were equal in quality, segregation did not violate the Equal Protection Clause of the Fourteenth Amendment. This case legitimized segregation for many decades, providing a legal basis for racial discrimination in various aspects of public life, including education, transportation, and more.

The other cases mentioned focus on different constitutional issues. Brown v. Board of Education, for example, later overturned Plessy v. Ferguson by declaring that segregation in public schools was inherently unequal and therefore unconstitutional. Roe v. Wade addressed the right to privacy regarding abortion laws, and Marbury v. Madison established the principle of judicial review. While each case is significant in U.S. legal history, they do not pertain to the establishment of "separate but equal" like Plessy v. Ferguson does.