If civil liberties is the point of discussion, then two cases must be put at the head of the list. Plessy v Ferguson (1896) and Brown v. Board of Ed. (1954). In Plessy, the court had held that certain southern state and local laws establishing segregation in public facilities (schools, bathrooms and the like) were constitutional; so long as the facilities in question were "separate but equal." The court never defined the term "equal" by the way; which led to the next 50 or so years of history in the south being a segregated history. Brown v Board, of course overturns the Plessy case... although once again, the court failed to express their legal meaning in their decision; saying that the state governments had to desegregate in a "timely fashion."