Landmark Cases

Landmark decisions establish a significant new legal principle or concept or otherwise that substantially changes the interpretation of existing law. Such a decision may settle the law in more than one way:

  • distinguishing a new principle that refines a prior principle, thus departing from prior practice without violating the rule of stare decisis;
  • establishing a “test” or a measurable standard that can be applied by courts in future decisions.

In the United States, landmark court decisions come most frequently from the Supreme Court. United States courts of appeals may also make such decisions, particularly if the Supreme Court chooses not to review the case or if it adopts the holding of the lower court; in Smith v. Collin, 439 U.S. 916 (1978), the Supreme Court denied the petition for certiorari and allowed the Seventh Circuit's opinion to stand: "if these civil rights are to remain vital for all, they must protect not only those society deems acceptable, but also those whose ideas it quite justifiably rejects and despises." Collin v. Smith, 578 F.2d 1197, 1210 (7th Cir. 1978). Although many cases from state supreme courts are significant in developing the law of that state, only a few are so revolutionary that they announce standards that many other state courts then choose to follow.


Many early court decisions involved defining the extent and limits of federalism. Federalism in the United States is the constitutional division of power between state governments and the federal government.

Hylton v. United States, 3 U.S. 171 (1796). A tax on the possession of goods is not a direct tax that must be apportioned among the states according to their populations. This case featured the first example of judicial review by the Supreme Court.

Marbury v. Madison, 5 U.S. 137 (1803). Section 13 of the Judiciary Act of 1789 is unconstitutional because it attempts to expand the original jurisdiction of the Supreme Court beyond that permitted by the Constitution. Congress cannot pass laws that contradict the Constitution. This case featured the first example of judicial nullification of a federal law and was the point at which the Supreme Court adopted a monitoring role over government actions.

Fletcher v. Peck, 10 U.S. 87 (1810). A state legislature can repeal a corruptly made law, but the Contract Clause of the Constitution prohibits the voiding of valid contracts made under such a law. This was the first case in which the Supreme Court struck down a state law as unconstitutional.

Martin v. Hunter's Lessee, 14 U.S. 304 (1816). Federal courts may review state court decisions when they rest on federal law or the federal Constitution. This decision provides for the uniform interpretation of federal law throughout the states.

McCulloch v. Maryland, 17 U.S. 316 (1819). The Necessary and Proper Clause of the Constitution grants to Congress implied powers for implementing the Constitution's express powers, and state actions may not impede valid exercises of power by the federal government.

Ableman v. Booth, 62 U.S. 506 (1859). State courts cannot issue rulings that contradict the decisions of federal courts.

Cooper v. Aaron, 358 U.S. 1 (1958). The states are bound by the decisions of the Supreme Court and cannot choose to ignore them.

Individual rights

Federal courts have decided many cases involving individual rights. Some cases involved discrimination based on race or ethnicity. Other cases involved discrimination based on sex or sexual orientation. Several cases involved rights to privacy and to obtain abortions.

Dred Scott v. Sandford, 60 U.S. 393 (1857). People of African descent that are slaves or were slaves and subsequently freed, along with their descendants, cannot be United States citizens. Consequently, they cannot sue in federal court. Additionally, slavery cannot be prohibited in U.S. territories before they are admitted to the Union as doing so would violate the Due Process Clause of the Fifth Amendment. After the Civil War, this decision was voided by the Thirteenth and Fourteenth Amendments to the Constitution.

Plessy v. Ferguson, 163 U.S. 537 (1896). Segregated facilities for blacks and whites are constitutional under the doctrine of separate but equal, which holds for close to 60 years until overruled by Brown v. Board of Education.

Schenck v. United States, 249 U.S. 47 (1919) Expressions in which the circumstances are intended to result in crime that poses a clear and present danger of succeeding can be punished without violating the First Amendment. The Court overruled Schenck in Brandenburg v. Ohio.

Cantwell v. Connecticut, 310 U.S. 296 (1940). The states cannot interfere with the free exercise of religion.

Chaplinsky v. New Hampshire, 315 U.S. 568 (1942). Fighting words—words that by their very utterance inflict injury or tend to incite an immediate breach of the peace—are not protected by the First Amendment.

Brown v. Board of Education, 347 U.S. 483 (1954). Segregated schools in the states are unconstitutional because they violate the Equal Protection Clause of the Fourteenth Amendment. The Court found that the separate but equal doctrine adopted in Plessy v. Ferguson “has no place in the field of public education.”

New York Times Co. v. Sullivan, 376 U.S. 254 (1964). Public officials, to prove they were libeled, must show not only that a statement is false, but also that it was published with malicious intent.

Griswold v. Connecticut, 381 U.S. 479 (1965). A Connecticut law that criminalizes the use of contraception by married couples is unconstitutional because all Americans have a constitutionally protected right to privacy.

Loving v. Virginia, 388 U.S. 1 (1967). Laws that prohibit interracial marriage (anti-miscegenation laws) are unconstitutional.

Brandenburg v. Ohio, 395 U.S. 444 (1969). The mere advocacy of the use of force or of violation of the law is protected by the First Amendment. Only inciting others to take direct and immediate unlawful action is without constitutional protection.

New York Times Co. v. United States, 403 U.S. 713 (1971). The federal government's desire to keep the Pentagon Papers classified is not strong enough to justify violating the First Amendment by imposing prior restraints on the material.

Roe v. Wade, 410 U.S. 113 (1973). Laws that restrict a woman's ability to have an abortion prior to viability are unconstitutional. Most restrictions during the first trimester are prohibited, and only health-related restrictions are permitted during the second trimester.

Miller v. California, 413 U.S. 15 (1973). To be obscene, a work must fail the Miller test, which determines if it has any “serious literary, artistic, political, or scientific value.”

Frontiero v. Richardson, 411 U.S. 677 (1973). Sex-based discriminations are inherently suspect. A statute that gives benefits to the spouses of male members of the uniformed services, but not to the spouses of female members, (on the assumption that only the former are dependent) is unconstitutional.

Buckley v. Valeo, 424 U.S. 1 (1976). Spending money to influence elections is a form of constitutionally protected free speech; therefore, federal limits on campaign contributions are constitutional in only a limited number of circumstances.

Regents of the University of California v. Bakke, 438 U.S. 265 (1978). Race-based set-asides in educational opportunities violate the Equal Protection Clause. This decision leaves the door open for the possibility of some use of race in admission decisions.

Batson v. Kentucky, 476 U.S. 79 (1986). Prosecutors may not use peremptory challenges to dismiss jurors based on their race.

Texas v. Johnson, 491 U.S. 397 (1989). A Texas law that criminalizes the desecration of the American flag is unconstitutional because it violates the First Amendment's protection of symbolic speech. This decision invalidates laws prohibiting flag desecration in 48 of the 50 states. Alaska and Wyoming had no such laws.

Planned Parenthood v. Casey, 505 U.S. 833 (1992). A woman is still able to have an abortion before viability, but several restrictions are now permitted during the first trimester. The strict trimester framework of Roe is discarded and replaced with the “undue burden” test.

J.E.B. v. Alabama ex rel. T.B., 511 U.S. 127 (1994). Prosecutors may not use peremptory challenges to dismiss jurors based on their sex.

Romer v. Evans, 517 U.S. 620 (1996). A Colorado state constitutional amendment that prevents homosexuals and bisexuals from being able to obtain protections under the law is a violation of the Equal Protection Clause of the Fourteenth Amendment.

Lawrence v. Texas, 539 U.S. 558 (2003). A Texas law that criminalizes consensual same-sex sexual conduct furthers no legitimate state interest and violates homosexuals' right to privacy under the Due Process Clause of the Fourteenth Amendment

Grutter v. Bollinger, 539 U.S. 306 (2003). A narrowly tailored use of race in student admission decisions may be permissible under the Equal Protection Clause because a diverse student body is beneficial to all students.

Citizens United v. Federal Election Commission, 558 U.S. 310 (2010). Limits on corporate and union political expenditures during election cycles violate the Free Speech Clause of the First Amendment. Corporations and labor unions can spend unlimited sums in support of or in opposition to candidates as long as the spending is independent of the candidates

United States v. Windsor, 570 U.S. 744 (2013). Section 3 of the Defense of Marriage Act, which defines—for federal law purposes—the terms “marriage” and “spouse” to apply only to marriages between one man and one woman, is a deprivation of the equal liberty of the person protected by the Due Process Clause of the Fifth Amendment. The federal government must recognize same-sex marriages that have been approved by the states.

Schuette v. Coalition to Defend Affirmative Action, 572 U.S. 291 (2014). A Michigan state constitutional amendment that bans affirmative action does not violate the Equal Protection Clause.

Obergefell v. Hodges, 576 U.S. ___ (2015). The Fourteenth Amendment requires a state to license a marriage between two people of the same sex with all the accompanying rights and responsibilities and to recognize a marriage between two people of the same sex when their marriage was lawfully licensed and performed out-of-state.

Whole Woman's Health v. Hellerstedt, 579 U.S. ___ (2016). Both the admitting-privileges and the surgical-center requirements place a substantial obstacle in the path of women seeking a pre-viability abortion, constitute an undue burden on abortion access, and thus violate the Constitution

Criminal law

The federal courts have interpreted criminal law over the years, defining the scope of constitutional rights.

Weeks v. United States, 232 U.S. 383 (1914). Evidence gathered by law enforcement in violation of the Fourth Amendment should be excluded from criminal proceedings. This “exclusionary rule” applied only to federal courts, not state courts.

Gideon v. Wainwright, 372 U.S. 335 (1963). All defendants have the right to an attorney and must be provided one by the state if they are unable to afford legal counsel.

Escobedo v. Illinois, 378 U.S. 478 (1964). A person in police custody has the right to speak to an attorney.

Miranda v. Arizona, 384 U.S. 436 (1966). Police must advise criminal suspects of their rights under the Constitution to remain silent, to consult with a lawyer, and to have one appointed to them if they are indigent. A police interrogation must stop if the suspect states that he or she wishes to remain silent.

In re Gault, 387 U.S. 1 (1967). Juvenile defendants are protected under the Due Process Clause of the Fourteenth Amendment.

Mapp v. Ohio, 367 U.S. 643 (1961). Evidence that is obtained in violation of the Fourth Amendment is inadmissible in state court. Notable for expanding the “exclusionary rule” originally articulated against only the federal government in Weeks v. United States.

Terry v. Ohio, 392 U.S. 1 (1968). Police may stop a person if they have a reasonable suspicion that the person has committed or is about to commit a crime and frisk the suspect for weapons if they have a reasonable suspicion that the suspect is armed and dangerous without violating the Fourth Amendment.

Bivens v. Six Unknown Named Agents, 403 U.S. 388 (1971). Individuals may sue federal government officials who have violated their Fourth Amendment rights even though such a suit is not authorized by law. The existence of a remedy for the violation is implied from the importance of the right that is violated.

United States v. United States District Court for the Eastern District of Michigan, 407 U.S. 297 (1972). Government officials must obtain a warrant before beginning electronic surveillance even if domestic security issues are involved. The “inherent vagueness of the domestic security concept” and the potential for abusing it to quell political dissent make the Fourth Amendment's protections especially important when the government engages in spying on its own citizens.

Georgia v. Randolph, 547 U.S. 103 (2006). Police cannot conduct a warrantless search in a home where one occupant consents and the other objects.

Riley v. California, 573 U.S. ___ (2014). Police must obtain a warrant in order to search digital information on a cell phone seized from an individual who has been arrested.

Carpenter v. United States, 585 U.S. ___ (2018). Government acquisition of cell-site records is a Fourth Amendment search, and, thus, generally requires a warrant

Capital punishment

The U.S. Supreme Court took up the issue of capital punishment beginning in 1972.

Furman v. Georgia, 408 U.S. 238 (1972). The arbitrary and inconsistent imposition of the death penalty violates the Eighth and Fourteenth Amendments and constitutes cruel and unusual punishment. This decision initiates a nationwide de facto moratorium on executions that lasts until the Supreme Court's decision in Gregg v. Georgia.

Gregg v. Georgia, 428 U.S. 153 (1976). Georgia's new death penalty statute is constitutional because it adequately narrows the class of defendants eligible for the death penalty. By evaluating the new death penalty statutes that had been passed by the states, the Supreme Court ended the moratorium on executions that began with its decision in Furman v. Georgia.

Ford v. Wainwright, 477 U.S. 399 (1986). A death sentence may not be imposed on the insane.

Roper v. Simmons, 543 U.S. 551 (2005). A death sentence may not be imposed on juvenile offenders.

Baze v. Rees, 553 U.S. 35 (2008). The three-drug cocktail used for performing executions by lethal injection in Kentucky (as well as virtually all of the states using lethal injection at the time) is constitutional under the Eighth Amendment.

Kennedy v. Louisiana, 554 U.S. 407 (2008). The death penalty is unconstitutional in all cases that do not involve murder or crimes against the state such as treason.