In Plessy v. Ferguson (1896), the U. S. Supreme Court established the general principle that: states could use poll taxes and literacy tests to establish voting qualifications.

states could not prevent blacks from voting just because their grandparents had been slaves.

states could require separate accommodations on trains, in schools, and the like, for blacks and whites as long as the accommodations were equal.

Congress could take away a state's seats in the U. S. House of Representatives if the state refused to allow blacks to vote in Congressional elections.