In which case did the Supreme Court uphold the constitutionality of racial segregation under the "separate but equal" doctrine?

The case that upheld the constitutionality of racial segregation under the "separate but equal" doctrine is Plessy v. Ferguson. In this landmark decision from 1896, the Supreme Court ruled that racially segregated facilities for African Americans and whites did not violate the Equal Protection Clause of the Fourteenth Amendment, so long as these facilities were of equal quality. This ruling effectively legitimized state laws that established racial segregation, providing a legal foundation for Jim Crow laws that enforced racial discrimination in many aspects of life, including education, transportation, and public accommodations.

Understanding this ruling is important in the context of American history because it illustrates how judicial interpretation played a significant role in shaping societal norms and policies regarding race. It wasn't until later cases, such as Brown v. Board of Education in 1954, that the "separate but equal" doctrine was finally overturned, leading to a significant shift in civil rights law and advancing the quest for equality in the United States.