Famous case law examples are the Supreme Court decisions that changed how American law works, and most of the ones people can name fall into a handful of areas: the power of the courts themselves, civil rights and equality, criminal procedure, privacy, and free speech. Case law is the body of legal rules judges create when they decide disputes, and once an appellate court resolves a question, that ruling binds every lower court in its jurisdiction under the principle of stare decisis. The cases below are the ones that show up in classrooms, court filings, and news coverage decades after they were decided.
Cases That Defined What Courts Can Do
Marbury v. Madison (1803)
Every other case on this list depends on Marbury. In the final hours of President John Adams’s term, William Marbury was promised a commission as a justice of the peace, but the paperwork was never delivered. He asked the Supreme Court to order the new Secretary of State, James Madison, to hand it over.
Chief Justice John Marshall concluded that Marbury deserved the commission but that the Court could not force its delivery. The Judiciary Act of 1789 gave the Supreme Court authority to issue that kind of order, yet the Constitution limited the Court’s original jurisdiction to a narrow set of cases. Because Congress cannot override the Constitution through ordinary legislation, Marshall declared that portion of the statute void.1Justia. Marbury v. Madison, 5 U.S. 137 (1803) The lasting principle: courts decide what the law means, and when a statute conflicts with the Constitution, the Constitution wins. That authority is called judicial review.
United States v. Lopez (1995)
Congress justifies much of its lawmaking under the Commerce Clause, which grants it power to regulate interstate commerce. For most of the twentieth century, courts read that authority broadly. In 1995, the Court drew a line. A federal law made it a crime to carry a gun near a school, and the Court struck it down because possessing a firearm in a school zone was not economic activity and did not substantially affect interstate commerce.2Justia. United States v. Lopez, 514 U.S. 549 (1995)
Lopez sorted Commerce Clause authority into three categories: the channels of interstate commerce, the people or things moving in it, and activities with a substantial economic effect on it. If a law does not fit one, Congress has exceeded its authority. It was the first time in nearly sixty years the Court told Congress it had gone too far.
Loper Bright Enterprises v. Raimondo (2024)
For forty years, courts followed a rule from a 1984 case called Chevron that required judges to defer to a federal agency’s interpretation of an ambiguous law, so long as the interpretation was reasonable. That gave enormous power to the executive branch, because agencies could effectively define the reach of their own authority whenever Congress left gaps.
In 2024, the Court overruled Chevron. It held that the Administrative Procedure Act requires judges to use their own independent judgment when deciding whether an agency has acted within a statute’s boundaries. Ambiguity does not automatically hand interpretive authority to the agency that enforces the law.3Justia. Loper Bright Enterprises v. Raimondo, 603 U.S. ___ (2024) Courts can still consider an agency’s reading; they are no longer obligated to accept it. This is the biggest shift in administrative law in decades.
Cases That Ended Legal Discrimination
Brown v. Board of Education (1954)
For more than half a century after Plessy v. Ferguson, states legally maintained racially segregated public schools on the theory that separate facilities could be equal. In Brown, the Court unanimously rejected that theory. Separating children by race in public schools, even where buildings and resources were comparable, created a sense of inferiority that undermined educational opportunity in ways impossible to measure with a ruler or a budget.4Justia. Brown v. Board of Education of Topeka, 347 U.S. 483 (1954)
The decision declared that segregated public schools violated the Equal Protection Clause of the Fourteenth Amendment. A follow-up ruling the next year, Brown II, ordered districts to desegregate “with all deliberate speed.”5National Archives. Brown v. Board of Education The fight over implementation lasted decades. The legal foundation was set: government-imposed racial separation was unconstitutional.
Loving v. Virginia (1967)
Virginia and fifteen other states still banned interracial marriage when Richard and Mildred Loving were prosecuted for theirs. The Court struck down the law unanimously, holding that marriage is a fundamental right and that restricting it through racial classifications violated both the Due Process and Equal Protection Clauses of the Fourteenth Amendment.6Justia. Loving v. Virginia, 388 U.S. 1 (1967) Every remaining state ban fell with it.
Obergefell v. Hodges (2015)
Almost fifty years after Loving, the Court applied similar reasoning to same-sex marriage. In a 5–4 decision, it held that the Fourteenth Amendment’s Due Process and Equal Protection Clauses guarantee same-sex couples the right to marry on the same terms as opposite-sex couples. The majority reasoned that marriage is a fundamental liberty tied to personal autonomy, intimate association, and the protection of families.7Legal Information Institute. Obergefell v. Hodges, 576 U.S. 644 (2015) Every state was required to issue marriage licenses to same-sex couples and to recognize same-sex marriages performed elsewhere.
Cases That Shape What Police Can Do
Miranda v. Arizona (1966)
Ernesto Miranda confessed to kidnapping and assault after two hours of police questioning without ever being told he had the right to remain silent or to have a lawyer present. His confession convicted him. The Court reversed and established the warnings now known by his name: before any custodial interrogation, police must inform a suspect of the right to remain silent, that anything said can be used in court, the right to an attorney, and that one will be appointed if the suspect cannot afford one.8Justia. Miranda v. Arizona, 384 U.S. 436 (1966)
Skip the warnings, and statements made during interrogation are generally inadmissible at trial. The rule rests on the Fifth Amendment’s protection against self-incrimination.
Gideon v. Wainwright (1963)
Clarence Earl Gideon was charged with a felony in Florida and asked the trial court to appoint him a lawyer because he could not afford one. The court refused. Gideon represented himself, lost, and wrote a handwritten petition to the Supreme Court from his cell arguing that the Sixth Amendment entitled him to counsel.
The Court agreed unanimously. It held that the right to an attorney in a criminal case is fundamental to a fair trial and that the Fourteenth Amendment requires states to provide lawyers to defendants who cannot pay.9Justia. Gideon v. Wainwright, 372 U.S. 335 (1963) Gideon was retried with counsel and acquitted. The ruling created the modern public defender system. One boundary worth knowing: the guarantee is for criminal cases. The Court later held that the Constitution does not automatically require a free lawyer in civil proceedings, even when jail time is possible for something like unpaid child support.10Justia. Turner v. Rogers, 564 U.S. 431 (2011)
Mapp v. Ohio (1961)
Cleveland police arrived at Dollree Mapp’s home looking for a bombing suspect. When she refused to let them in without a warrant, officers forced their way through the door. They never produced a valid warrant. During the search, they found materials they deemed obscene and used them to convict her.
The Court reversed and established the exclusionary rule for state courts: evidence obtained through an unconstitutional search cannot be used in a state criminal trial.11Justia. Mapp v. Ohio, 367 U.S. 643 (1961) Federal courts had followed the rule for decades; Mapp extended it to every courtroom in the country through the Fourteenth Amendment.
Katz v. United States (1967)
The Fourth Amendment originally focused on physical intrusion. If police did not physically enter your home or rifle through your belongings, there was no “search.” Katz changed that. FBI agents attached a listening device to the outside of a public phone booth to record a suspect’s conversations. No one broke in or touched his property, yet the Court ruled the recording was an unconstitutional search.12Justia. Katz v. United States, 389 U.S. 347 (1967)
The lasting contribution came from Justice Harlan’s concurrence, which created a two-part test still used today: the person must have shown an actual expectation of privacy, and that expectation must be one society recognizes as reasonable. “The Fourth Amendment protects people, not places,” the Court wrote, untethering privacy from physical property.
Riley v. California (2014)
Police have long been allowed to search items found on someone they arrest, mainly to protect officer safety and prevent evidence destruction. In 2014, the Court unanimously held that this exception does not extend to the digital contents of a cell phone. A phone’s data cannot be used as a weapon, and the sheer volume of personal information stored on a modern device makes it qualitatively different from a wallet or a cigarette pack.13Justia. Riley v. California, 573 U.S. 373 (2014) Officers who want to examine the digital contents of a phone need a warrant.
Cases About Speech and the Press
Tinker v. Des Moines (1969)
Three students wore black armbands to school to protest the Vietnam War and were suspended. The Court ruled the suspensions violated the First Amendment. Students do not lose their right to express themselves at the schoolhouse door, and a school cannot punish peaceful, nondisruptive expression simply because administrators disagree with the message.14Justia. Tinker v. Des Moines Independent Community School District, 393 U.S. 503 (1969)
The standard: schools can restrict student speech only when it causes or is reasonably likely to cause a substantial disruption or invades the rights of others. Later decisions carved out exceptions for speech that is vulgar, school-sponsored, or promotes illegal drug use, but Tinker remains the baseline.
New York Times Co. v. Sullivan (1964)
An Alabama official sued The New York Times over a fundraising advertisement that contained minor factual errors about police conduct during civil rights protests. A local jury awarded $500,000. The Court reversed, holding that the First Amendment requires public officials suing for defamation to prove “actual malice,” meaning the publisher either knew the statement was false or acted with reckless disregard for whether it was true.15Justia. New York Times Co. v. Sullivan, 376 U.S. 254 (1964)
That is an intentionally high bar. Without it, every factual error in a story about a politician could become a lawsuit. The actual malice standard was later extended to public figures generally. Private plaintiffs are treated under a different framework the Court set out in Gertz v. Robert Welch, Inc. (1974).16Legal Information Institute. Gertz v. Robert Welch, Inc., 418 U.S. 323 (1974)
Citizens United v. FEC (2010)
Federal law prohibited corporations and unions from spending general treasury funds on ads that expressly supported or opposed political candidates. In Citizens United, the Court struck down the ban, holding that the First Amendment protects political speech regardless of whether the speaker is an individual, a corporation, or a union.17Justia. Citizens United v. Federal Election Commission, 558 U.S. 310 (2010)
The Court drew a line between independent expenditures, which are protected, and direct contributions to candidates or parties, which are still subject to limits. The ruling opened the door to the super PACs that now dominate election spending.
Cases About Privacy and Bodily Autonomy
Griswold v. Connecticut (1965)
Connecticut made it a crime to use contraceptives, even for married couples. The Court struck down the law, reasoning that several guarantees in the Bill of Rights create overlapping zones of privacy the government cannot invade. A married couple’s decisions about contraception fell squarely within that protected zone.18Justia. Griswold v. Connecticut, 381 U.S. 479 (1965)
Griswold introduced the idea that the Constitution protects fundamental rights even when no specific clause spells them out, a concept known as substantive due process. That framework became the legal scaffolding for decades of privacy rulings.
Roe v. Wade (1973)
Building on Griswold, the Court held in Roe that the Due Process Clause of the Fourteenth Amendment protected a woman’s decision to end a pregnancy. The ruling created a trimester system: during the first trimester, the decision belonged to the woman and her doctor; in the second, states could regulate to protect maternal health; in the third, after viability, states could restrict or ban abortion except when the woman’s life or health was at risk.19Justia. Roe v. Wade, 410 U.S. 113 (1973)
Roe was modified but not overruled by Planned Parenthood v. Casey in 1992, which replaced the trimester framework with an “undue burden” test. Both decisions rested on the same substantive due process theory.
Dobbs v. Jackson Women’s Health Organization (2022)
In 2022, the Court overruled both Roe and Casey. The majority in Dobbs held that the Constitution does not confer a right to abortion and that neither the text nor the history and tradition of the Fourteenth Amendment supports one. The Court concluded that Roe had been “egregiously wrong” from the start and returned authority to regulate abortion to elected legislators at the state level.20Supreme Court of the United States. Dobbs v. Jackson Women’s Health Organization, 597 U.S. 215 (2022)
Dobbs is as much a case about precedent as about abortion. Within months, states split sharply, some enacting near-total bans and others moving to protect abortion access in their state constitutions.21Congress.gov. Abortion, Dobbs v. Jackson Women’s Health Organization, and Post-Dobbs Doctrine The legal lesson is one that ties this whole list together: stare decisis is a strong presumption, not an unbreakable rule, and even the most famous cases stand only until a later Court decides they were wrongly reasoned.