Read the excerpt from the Supreme Court’s ruling in Plessy v. Ferguson.

That petitioner was a citizen of the United States and a resident of the State of Louisiana, of mixed descent . . . on June 7, 1892, he engaged and paid for a first class passage on the East Louisiana Railway . . . and thereupon entered a passenger train, and took possession of a vacant seat in a coach where passengers of the white race were accommodated; that such railroad company was incorporated by the laws of Louisiana as a common carrier, and was not authorized to distinguish between citizens according to their race. But, notwithstanding this, petitioner was required by the conductor, under penalty of ejection from said train and imprisonment, to vacate said coach and occupy another seat in a coach assigned by said company for persons not of the white race.

How does this relate to the premises of Brown v. Board of Education?
The Brown case addresses whether localities have the authority to label individuals by race.
The Brown case addresses whether the laws of Southern states are racially biased.
The Brown case addresses whether penalties and punishments can legally vary by race.
The Brown case addresses whether facilities separated by race are permissible by law.