Plessy & Ferguson

instapundit linked to this - i'll link to this:

The arbitrary separation of citizens on the basis of race while they are on a public highway is a badge of servitude wholly inconsistent with the civil freedom and the equality before the law established by the Constitution. It cannot be justified upon any legal grounds.

If evils will result from the commingling of the two races upon public highways established for the benefit of all, they will be infinitely less than those that will surely come from state legislation regulating the enjoyment of civil rights upon the basis of race.