On June 7, 1892, Homer Plessy bought a first-class ticket in New Orleans and sat in a car reserved for white passengers. He was arrested, which was the plan: a group of New Orleans civil rights activists had arranged the arrest to test Louisiana's Separate Car Act in court. Four years later the Supreme Court ruled against him, 7–1. It took until 1954 for the Court to reject the idea his case stood for.
This lesson follows the Supreme Court from Plessy v. Ferguson (1896) to Roe v. Wade (1973). These cases sit in Periods 6, 7 and 8 of AP US History; Dobbs (2022) belongs to Period 9.
The big themes
- The 14th Amendment does the heavy lifting. Its equal protection and due process clauses underpin most of these cases.
- The Court changes its mind. Rulings that stood for decades were later reversed, as the country, the arguments and the justices changed.
- Rights grow unevenly. In wartime the Court often sided with the government; the Warren Court later expanded individual liberties.
Race and citizenship, 1896 to 1954
Plessy accepted state-required segregation, and Justice John Marshall Harlan wrote the lone dissent. Two years later, United States v. Wong Kim Ark (1898) confirmed that a child born in the United States to Chinese parents was a citizen. In 1954 Hernandez v. Texas held that excluding Mexican Americans from juries violated equal protection. Two weeks later, Brown v. Board of Education ruled segregated public schools unconstitutional. Brown II (1955) asked for desegregation "with all deliberate speed," and many districts delayed for years.
Business, labor and the New Deal
In Lochner v. New York (1905) the Court struck down a limit on bakers' hours as a violation of "freedom of contract." In Muller v. Oregon (1908) it upheld hours limits for women, persuaded by Louis Brandeis's brief full of social data, though its reasoning assumed women were weaker. In Schechter Poultry Corp. v. United States (1935) a unanimous Court struck down codes under the National Industrial Recovery Act. From 1937 the Court began upholding economic regulation, and Roosevelt's appointees soon became its majority.
Wartime and civil liberties
Schenck v. United States (1919) upheld a conviction for antidraft leaflets under the "clear and present danger" test. Korematsu v. United States (1944) upheld the exclusion of Japanese Americans from the West Coast. Buck v. Bell (1927) upheld forced sterilization for eugenic purposes. Korematsu is often cited as one of the Court's worst decisions, and Buck remains widely condemned.
The Warren Court and after
Under Chief Justice Earl Warren (1953–1969) the Court expanded rights:
- Defendants: Mapp v. Ohio (1961), Gideon v. Wainwright (1963), Miranda v. Arizona (1966).
- Religion and speech: Engel v. Vitale (1962), Tinker v. Des Moines (1969).
- Equality and voting: Baker v. Carr (1962), Heart of Atlanta Motel (1964), Loving v. Virginia (1967), Jones v. Alfred H. Mayer Co. (1968).
- Privacy: Griswold v. Connecticut (1965).
Critics, many of them conservatives, argued the Court was making policy that belonged to elected lawmakers. Roe v. Wade (1973), decided after Warren retired, extended Griswold's privacy reasoning to abortion. It became one of the most debated rulings in US history. In 2022 Dobbs v. Jackson Women's Health Organization overruled it and left abortion law to the states.
Common mistakes students make
- Saying Brown ended segregation. It ruled school segregation unconstitutional; enforcement took years, plus the Civil Rights Act of 1964.
- Saying Miranda rights must be read at arrest. The warnings are required before police question someone in custody.
- Treating "fire in a crowded theater" as the current law. Holmes's line in Schenck was an illustration, not the test itself, and Brandenburg v. Ohio (1969) effectively replaced his test.
- Writing about Roe as current law. Since 2022 it is history; name Dobbs.
Frequently asked questions
Which Supreme Court cases should I know for APUSH?
The course framework and its optional sources mention cases such as Plessy, Brown, Gideon and Loving; know what each decided and how it connects to its period.
What did Plessy v. Ferguson decide?
It upheld state laws requiring separate railroad cars by race, giving legal cover to segregation until Brown rejected "separate but equal" in public schools.
What was the Warren Court known for?
Rulings from 1953 to 1969 that expanded civil rights, the rights of criminal defendants and equal voting districts.
Is Roe v. Wade still law?
No. Dobbs v. Jackson Women's Health Organization overruled it in 2022, so abortion law is now set mainly by the states.
Try it
Say each answer before you flip the card. Then put Plessy (1896) and Brown (1954) side by side: same Constitution, opposite answers. What changed, and why then?
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