Final answer:
The Supreme Court ruled in Brown v. Board of Education that racial segregation in public schools violated the Equal Protection Clause of the Fourteenth Amendment and had a detrimental psychological impact on black children, nullifying the 'separate but equal' doctrine from Plessy v. Ferguson.
Step-by-step explanation:
The Supreme Court's ruling in the landmark case Brown v. Board of Education of 1954 held that racial segregation in public schools was unconstitutional. The Court's unanimous decision was grounded in the Equal Protection Clause of the Fourteenth Amendment. It stated that no state shall deny any person within its jurisdiction "the equal protection of the laws." Furthermore, the ruling emphasized that segregated schools, even if equal in quality, could never be truly equal because they imparted a sense of inferiority amongst the students who were segregated.
This sentiment was supported by social science studies, which indicated that segregation had a detrimental psychological impact on Black children. The decision effectively overturned the "separate but equal" doctrine of Plessy v. Ferguson, marking a crucial step forward for civil rights and the desegregation of public schools in the United States.