Final answer:
The decision indicative of the Supreme Court's earlier interpretation of the Fourteenth Amendment concerning civil rights and state discretion is Plessy v. Ferguson, which established the "separate but equal" doctrine that allowed for racial segregation. It was overturned by Brown v. Board of Education, which asserted that racially segregated schools were inherently unequal.
Step-by-step explanation:
The Fourteenth Amendment has been pivotal in shaping the landscape of civil rights in the United States. In the decades following the Civil War, the Supreme Court made crucial decisions that interpreted this amendment, particularly relating to state discretion in civil rights matters. One such decision, indicative of the Court's interpretation during this period, was Plessy v. Ferguson (1896). This ruling established the doctrine of "separate but equal," which allowed for racial segregation as long as the separate facilities provided for black Americans were purportedly equal to those for white Americans. However, it was challenged and eventually overturned by Brown v. Board of Education (1954), which ruled that segregation in public schools was unconstitutional as the segregated schools were inherently unequal and violated the equal protection clause of the Fourteenth Amendment.
The Plessy v. Ferguson ruling had far-reaching implications, facilitating racial segregation under the guise of equality for almost 60 years. It was not until the landmark decision in Brown v. Board of Education that the Supreme Court acknowledged the inherent inequality in segregated schools and began the process of dismantling the institutionalized segregation that violated civil rights guaranteed by the Fourteenth Amendment.