Major Supreme Court Decisions

Why This Matters

The Supreme Court doesn't just settle legal disputes—it shapes the fundamental rules of American life. When you study landmark cases, you're really studying how the Constitution gets interpreted and reinterpreted across generations. These decisions reveal the ongoing tension between federal and state power, the expansion (and sometimes contraction) of individual rights, and the Court's role as the ultimate check on the other branches of government.

You're being tested on more than case names and dates. AP exams expect you to understand why a decision mattered, what constitutional principle it established, and how it connects to broader patterns in American history. Don't just memorize facts—know what concept each case illustrates: judicial review, due process, equal protection, federalism, civil liberties. That's what earns you points on FRQs.

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Establishing Judicial Power

Before the Court could protect rights or limit government, it first had to establish its own authority. These cases defined the judiciary's role in the constitutional system.

Marbury v. Madison (1803)

• Judicial review—the power to strike down laws conflicting with the Constitution—was established here, making this the foundation of Supreme Court authority
• Chief Justice John Marshall used a seemingly minor dispute to claim enormous power for the judiciary without directly confronting President Jefferson
• Checks and balances gained teeth: Congress and the President now faced a co-equal branch that could void their actions

United States v. Nixon (1974)

• Executive privilege exists but is not absolute—the Court ruled unanimously that Nixon must release the Watergate tapes
• "No person is above the law" became the defining principle, directly leading to Nixon's resignation two weeks later
• Separation of powers was reinforced: the judiciary can compel even the President to comply with legal processes

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Civil Rights and Equal Protection

The Fourteenth Amendment promises "equal protection of the laws," but the Court's interpretation of that phrase has shifted dramatically. These cases trace the arc from legalized discrimination to constitutional equality.

Dred Scott v. Sandford (1857)

• African Americans could not be citizens—the Court ruled they had no standing to sue, regardless of free or enslaved status
• Missouri Compromise declared unconstitutional, removing congressional power to restrict slavery in territories and inflaming sectional tensions
• States' rights over federal power was emphasized, making this decision a catalyst for the Civil War

Plessy v. Ferguson (1896)

• "Separate but equal" doctrine upheld racial segregation as constitutional under the Fourteenth Amendment
• State-sponsored discrimination gained legal legitimacy, enabling Jim Crow laws across the South for nearly sixty years
• Justice Harlan's dissent—"the Constitution is colorblind"—would eventually become the majority view

Brown v. Board of Education (1954)

• Overturned Plessy, declaring that segregated schools are "inherently unequal" and violate equal protection
• Unanimous decision under Chief Justice Earl Warren gave the ruling moral and legal weight during a divided era
• Civil Rights Movement gained crucial legal backing, though implementation ("with all deliberate speed") proved slow and contested

Obergefell v. Hodges (2015)

• Same-sex marriage legalized nationwide—state bans violated both due process and equal protection under the Fourteenth Amendment
• Marriage as a fundamental right was affirmed, extending the logic of earlier cases like Loving v. Virginia (interracial marriage)
• LGBTQ+ civil rights achieved a landmark victory, though debates over religious liberty exemptions continue

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Rights of the Accused

The Bill of Rights protects individuals from government overreach, but those protections meant little until the Court applied them to state criminal proceedings. These cases transformed criminal justice.

Gideon v. Wainwright (1963)

• Right to counsel guaranteed for all criminal defendants, even those who cannot afford an attorney—Sixth Amendment incorporated against states
• Clarence Gideon petitioned the Court from prison in a handwritten letter, and his retrial with a lawyer resulted in acquittal
• Public defender systems expanded nationwide as states scrambled to comply with the ruling

Miranda v. Arizona (1966)

• Miranda warnings required before police interrogation: right to remain silent, right to an attorney, statements can be used against you
• Fifth Amendment protection against self-incrimination now had practical teeth in every police station
• Confession reliability improved as coerced statements became inadmissible, though critics argued it hampered law enforcement

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Privacy and Personal Liberty

The Constitution doesn't explicitly mention "privacy," but the Court has found it implied in several amendments. These cases define—and contest—the boundaries of personal autonomy.

Roe v. Wade (1973)

• Constitutional right to privacy extended to a woman's decision to have an abortion, grounded in the Fourteenth Amendment's due process clause
• Trimester framework balanced state interests against individual rights, allowing more regulation as pregnancy progressed
• Ongoing controversy made this one of the most debated decisions in Court history; it was overturned by Dobbs v. Jackson (2022)

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Money, Speech, and Democracy

The First Amendment protects political speech, but what counts as "speech"? These cases wrestle with the relationship between money, expression, and democratic participation.

Citizens United v. Federal Election Commission (2010)

• Corporate political spending protected as free speech under the First Amendment—restrictions on independent expenditures struck down
• Super PACs emerged, allowing unlimited fundraising and spending on elections as long as they don't coordinate directly with campaigns
• Democratic debate intensified over whether money equals speech and whether corporations deserve the same rights as individuals

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Quick Reference Table

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Self-Check Questions

1. Which two cases both relied on the Fourteenth Amendment's equal protection clause but reached opposite conclusions about segregation, and what changed between them?

2. Gideon v. Wainwright and Miranda v. Arizona are often grouped together as part of the "due process revolution." What specific constitutional amendment does each case interpret, and how do they work together to protect the accused?

3. Compare Marbury v. Madison and United States v. Nixon: both limited government power, but which branch did each case check? Why are both essential examples of judicial review?

4. If an FRQ asked you to trace the expansion of civil rights through Supreme Court decisions, which three cases would you select and why? Consider how they build on each other chronologically.

5. Citizens United v. FEC remains controversial. What First Amendment principle did the Court use to justify its decision, and what is the main criticism of treating campaign spending as protected speech?