In the 1896 case Plessy v. Ferguson, the U.S. Supreme Court upheld the constitutionality of
A'separate but equal' racial segregation
Bthe principle of judicial review
Ca national income tax
Dthe direct election of senators
Explanation
Plessy v. Ferguson (1896) legalized 'separate but equal' segregation, which stood until Brown v. Board of Education (1954).