The amendment grants citizenship to "all persons born or naturalized in the United States" which included former slaves that were freed after the Civil War.
Plessy v. Ferguson: They went through segregation "Equal but separate accommodation" did not violate the 14th Amendment.
Brown v. Board of Education: Black school children wished to go to white schools. Court ruled the doctrine of separation but equal has no place and separate education facilities are inherently unequal. Courts ruled the schools integrate led to civil rights changes