How did the plessy decision overturned?

In 1954, sixty years after Plessy v. Ferguson, the Supreme Court ruled unanimously in Brown v. Board of Education that “separate but equal” was unconstitutional under the Equal Protection Clause of the Fourteenth Amendment.

Explanation:

In 1954, Brown v. Board of Education overturned Plessy, finding that "separate but equal" was invalid and banning racial segregation. Southern states didn't give in easily, and the threat of military force was necessary in some instances to enforce desegregation.

maybe #3? try that i think its correct

study of past cultures