Brown v. Board of Education

This landmark case nearly 60 years later destroyed the states rights to separate their citizens from U.S. citizens, and both statuses were equalized, and the states were required to NOT treat their citizens any differently from U.S. citizens.

https://www.uscourts.gov/educational-resources/educational-activities/history-brown-vboard-education-re-enactment
In 1954: “When the cases came before the Supreme Court in 1952, the Court consolidated all five cases under the name of Brown v. Board of Education. Marshall personally argued the case before the Court. Although he raised a variety of legal issues on appeal, the most common one was that separate school systems for blacks and whites were inherently unequal, and thus violate the "equal protection clause" of the Fourteenth Amendment to the U.S. Constitution. Furthermore, relying on sociological tests, such as the one performed by social scientist Kenneth Clark, and other data, he also argued that segregated school systems had a tendency to make black children feel inferior to white children, and thus such a system should not be legally
permissible.”