Plessy v Ferguson.
Browder v Gayle ended segregation in Alabama public transportation, Brown v BOE ended segregation in public schools, tinker v Des Moines allowed students to have freedom of speech. So it must be Plessy v Ferguson. Because it did not end segregation, but rather involved the phrase ‘separate but equal’. Plessy v Ferguson is the closest answer. Sorry if I got it wrong. God bless you