Plessy v. Ferguson and Brown v. Board of Education.
Plessy v. Ferguson upheld the constituionality of Jim Crow Laws stating that as long as the two races were equal and had access to facilities of equal quality, it was not illegal to seperate. Brown v. Board of Education was the court case that outlawed segregation by providing evidence that African Americans were not given access to bathrooms, train cars, waiting rooms, etcof equal stature. This went against "seperate but equal" and thus made Jim Crow Segregation illegal.