Final answer:
The Plessy v. Ferguson Supreme Court case in 1896 declared that segregation was permissible under the "separate-but-equal" doctrine. This decision was central to upholding Jim Crow laws until it was overturned by Brown v. Board of Education in 1954, which ruled that segregated educational facilities were inherently unequal.
Step-by-step explanation:
Plessy v. Ferguson: The "Separate-But-Equal" Doctrine
The court case that said segregation was allowed as long as "separate-but-equal" facilities were provided is known as Plessy v. Ferguson. This landmark decision was made by the U.S. Supreme Court in 1896 and it upheld the constitutionality of racial segregation laws for public facilities as long as the segregated facilities were equal in quality - a doctrine that came to be known as "separate but equal." This decision served as a cornerstone for the extensive segregation and the disenfranchisement of African Americans, mostly in the Southern states, under the Jim Crow laws. It wasn't until the 1954 Supreme Court decision in Brown v. Board of Education that the principle of "separate but equal" was found to be inherently unequal in the context of public education and thus unconstitutional, which helped lead to the end of de jure segregation in the United States.
De jure segregation, racial discrimination, and the quality of facilities provided under the "separate but equal" doctrine became central issues for the Civil Rights Movement, leading to numerous legal challenges and social demands for equal rights and treatment. The Plessy v. Ferguson case had significant and long-lasting effects on U.S. society, and its eventual overturning marked a major victory for civil rights advocates.