Ten Supreme Court cases everyone should know form the backbone of American constitutional law: they established the judiciary’s power to strike down laws, defined the balance between federal and state authority, dismantled legal segregation, set the ground rules for police and prosecutors, and drew the current boundaries around marriage and bodily autonomy. Each decision resolved a specific dispute, but the principles announced in these rulings shape every courtroom and legislature in the country today.
Foundations of Government Power
Marbury v. Madison (1803)
The Supreme Court’s most important power came from a fight over an undelivered appointment. When President John Adams left office in 1801, several judicial commissions he had signed never reached their intended recipients. William Marbury, appointed a justice of the peace, asked the Court to order Secretary of State James Madison to hand over the paperwork.
Chief Justice John Marshall agreed Marbury deserved the commission, but the law Marbury relied on had a fatal flaw. Section 13 of the Judiciary Act of 1789 tried to give the Court original jurisdiction over cases like his, while Article III of the Constitution limited the Court’s original jurisdiction to a narrower set of disputes. Marshall concluded that Congress had exceeded what the Constitution allowed, and Section 13 was invalid.1Justia. Marbury v. Madison
The principle that followed mattered far more than the outcome: when a federal law conflicts with the Constitution, the Constitution wins, and the judiciary decides. This doctrine of judicial review gave courts the authority to strike down legislation, a power the entire federal court system depends on.2Constitution Annotated. Marbury v. Madison and Judicial Review
McCulloch v. Maryland (1819)
Sixteen years later, the Court addressed the other defining question of early American government: how much power does the federal government have compared to the states? Maryland had imposed a $15,000 annual tax on any bank not chartered by the state, targeting the Second Bank of the United States. James McCulloch, a cashier at the Baltimore branch, refused to pay.3Justia. McCulloch v. Maryland
Two questions followed. Could Congress create a national bank at all, given that the Constitution never explicitly mentions one? The Court said yes. The Necessary and Proper Clause in Article I lets Congress pass laws that carry out its listed responsibilities, even when those laws go beyond what the Constitution specifically names.4Constitution Annotated. Overview of Necessary and Proper Clause Could Maryland tax a federal institution? Absolutely not. Marshall wrote that the power to tax is the power to destroy, and the Supremacy Clause in Article VI places federal law above state mandates in areas of national concern.3Justia. McCulloch v. Maryland
Together, Marbury and McCulloch drew the blueprint for how government power works in the United States. Courts police the boundaries of the Constitution, and when federal and state authority collide, federal law prevails.
Ending Racial Discrimination Under the Fourteenth Amendment
Brown v. Board of Education (1954)
For nearly sixty years after Plessy v. Ferguson approved racial segregation, states maintained separate schools for Black and white children on the theory that separate facilities could be equal. Brown consolidated lawsuits from multiple states where Black children had been refused admission to white public schools.5Justia. Brown v. Board of Education of Topeka
Chief Justice Earl Warren’s opinion did not compare buildings and textbooks. It examined what segregation did to children. The unanimous conclusion: separate educational facilities are inherently unequal because they stamp minority students with a badge of inferiority. Segregated schools violated the Equal Protection Clause of the Fourteenth Amendment.5Justia. Brown v. Board of Education of Topeka
A year later, Brown II directed school systems to integrate “with all deliberate speed,” a phrase that gave local districts significant leeway.6National Archives. Brown v. Board of Education (1954) Desegregation dragged on for decades in many places, but the constitutional rule was settled.
Loving v. Virginia (1967)
Richard Loving, a white man, and Mildred Jeter, a woman of African American and Native American descent, married in Washington, D.C., in 1958 because Virginia’s Racial Integrity Act of 1924 prohibited interracial marriage. After returning home, they were indicted, pleaded guilty, and given a choice: one year in prison or leave the state for 25 years.7Justia. Loving v. Virginia
They chose exile, then fought their way back. A unanimous Supreme Court struck down Virginia’s law, holding that anti-miscegenation statutes served no legitimate purpose beyond racial discrimination and violated both the Equal Protection and Due Process Clauses of the Fourteenth Amendment.8Supreme Court of the United States. Loving v. Virginia The Court declared marriage a fundamental right that government cannot restrict through racial classifications, a framework that would matter decades later in cases about who else could marry.
What Police and Courts Must Do
Mapp v. Ohio (1961)
In 1957, Cleveland police showed up at Dollree Mapp’s home looking for a bombing suspect. When she refused to let them in without a search warrant, officers waited three hours, then forced their way through her door. They never found the suspect. They did find books and pictures they deemed obscene, and prosecutors charged Mapp with possessing them. No valid warrant was ever produced at trial.9Justia. Mapp v. Ohio
The Fourth Amendment had long prohibited unreasonable searches, but that protection had uneven teeth. Federal courts threw out illegally obtained evidence; many state courts did not. Mapp closed the gap. Evidence obtained through an unconstitutional search cannot be used at trial in any court.9Justia. Mapp v. Ohio A sloppy warrant or a forced entry can now sink an entire prosecution.
Gideon v. Wainwright (1963)
Clarence Earl Gideon was charged with breaking into a Florida poolroom, a felony under state law. He asked the judge to appoint a lawyer. The judge refused, explaining that Florida only provided free attorneys in death penalty cases. Gideon represented himself, was convicted, and received a five-year sentence.10Justia. Gideon v. Wainwright
From prison, Gideon handwrote a petition to the Supreme Court. The justices unanimously agreed with him. The right to an attorney is so fundamental to a fair trial that the Fourteenth Amendment requires every state to provide one for any felony defendant who cannot afford to hire their own.10Justia. Gideon v. Wainwright The modern public defender system grew from this ruling.
Miranda v. Arizona (1966)
Ernesto Miranda was arrested, taken to a police station, and interrogated for two hours. He signed a written confession. No one told him he had the right to remain silent or speak with an attorney first.11Justia. Miranda v. Arizona
The Supreme Court held that the Fifth Amendment’s protection against self-incrimination applies during police interrogations, not only at trial. Custodial interrogation is inherently coercive, and without specific safeguards, any confession risks being involuntary. Before questioning, police must tell a suspect they have the right to remain silent, that anything they say can be used against them in court, that they have the right to an attorney, and that if they cannot afford one, an attorney will be provided.11Justia. Miranda v. Arizona Skip these warnings and any resulting statements are generally excluded from evidence.
Personal Life and the Constitution
Roe v. Wade (1973) and Dobbs v. Jackson Women’s Health Organization (2022)
A Texas woman using the pseudonym Jane Roe challenged a state law banning abortion except to save the mother’s life. The Court ruled 7-2 that the Fourteenth Amendment’s Due Process Clause protects a right to privacy broad enough to cover the decision to end a pregnancy. The opinion set a trimester framework: in the first trimester the decision belonged to the woman and her physician; in the second the state could regulate the procedure to protect maternal health; after viability the state could prohibit abortion except when necessary to preserve the life or health of the mother.12Justia. Roe v. Wade
That framework governed abortion law for nearly fifty years. Dobbs ended it. Mississippi had banned most abortions after fifteen weeks, well before the viability line Roe and later Planned Parenthood v. Casey had drawn. The Court’s majority held that the Constitution does not mention abortion and that no such right is implicitly protected. The justices concluded the right to abortion was not deeply rooted in American legal history and explicitly overturned both Roe and Casey.13Supreme Court of the United States. Dobbs v. Jackson Women’s Health Organization
Dobbs returned authority over abortion regulation to state legislatures. Some states moved to ban the procedure almost entirely, others enacted protections. A person’s ability to obtain an abortion now depends heavily on geography.
Obergefell v. Hodges (2015)
Same-sex couples in multiple states sued after being denied marriage licenses or refused recognition of marriages performed elsewhere. The Court ruled 5-4 that the Fourteenth Amendment’s Due Process and Equal Protection Clauses guarantee same-sex couples the same right to marry that opposite-sex couples have always enjoyed.14Justia. Obergefell v. Hodges
The majority identified four principles: marriage is essential to individual autonomy; it supports a two-person union of unique importance; it safeguards children and families; and it is a keystone of the nation’s social order. Excluding same-sex couples inflicted real harm while serving no legitimate government interest.15United States Department of Justice. Obergefell v. Hodges Every state must now issue marriage licenses to same-sex couples and recognize same-sex marriages performed in other states.
Congress added a statutory backstop in 2022 with the Respect for Marriage Act. Any marriage valid in the state where it was performed must receive full recognition under federal law, and no state official may refuse to honor a marriage from another state based on the sex, race, or ethnicity of the couple.16Office of the Law Revision Counsel. 28 USC 1738C – Certain Acts, Records, and Proceedings and the Effect Thereof The law also repealed the Defense of Marriage Act and created a private right of action for individuals who face discrimination.17Office of the Law Revision Counsel. 1 USC 7 – Marriage These protections now exist in federal statute regardless of future Court decisions.