Case briefs

Landmark case briefs with facts, ratio & judgment.

Browse 52 source-linked case summaries searchable by name, citation, court, jurisdiction, and legal principle.

Marbury v. Madison

constitutional law

5 U.S. (1 Cranch) 137 (1803)

Supreme Court of the United States · 1803 · United States

Issue: Could the Supreme Court issue a writ of mandamus under the Judiciary Act of 1789?
Held: No. The statutory grant of original jurisdiction was unconstitutional.
Ratio: Federal courts have authority to review legislative acts for constitutional validity.

constitutional law

federal courts law

McCulloch v. Maryland

constitutional law

17 U.S. (4 Wheat.) 316 (1819)

Supreme Court of the United States · 1819 · United States

Issue: Did Congress have power to charter the bank, and could Maryland tax it?
Held: Congress had implied power to create the bank, and Maryland could not tax it.
Ratio: Congress may use implied powers reasonably adapted to enumerated powers; states may not impede valid federal operations.

constitutional law

tax law

Gibbons v. Ogden

constitutional law

22 U.S. (9 Wheat.) 1 (1824)

Supreme Court of the United States · 1824 · United States

Issue: Did the Commerce Clause allow Congress to regulate interstate navigation?
Held: Yes. Navigation was commerce, and the federal license controlled.
Ratio: The Commerce Clause reaches interstate navigation and displaces conflicting state monopolies.

constitutional law

commercial law

Dred Scott v. Sandford

constitutional law

60 U.S. (19 How.) 393 (1857)

Supreme Court of the United States · 1857 · United States

Issue: Could Scott sue in federal court and did Congress have power to restrict slavery in territories?
Held: The Court held against Scott; the decision was later displaced by constitutional amendment.
Ratio: The decision is not good law and is studied as a repudiated constitutional failure.

constitutional law

legal history

Plessy v. Ferguson

constitutional law

163 U.S. 537 (1896)

Supreme Court of the United States · 1896 · United States

Issue: Did state-mandated racial segregation violate equal protection?
Held: The Court upheld segregation; the rule was later repudiated.
Ratio: The case is overruled and studied for the rejected separate-but-equal doctrine.

constitutional law

civil rights law

Brown v. Board of Education

constitutional law

347 U.S. 483 (1954)

Supreme Court of the United States · 1954 · United States

Issue: Does racial segregation in public schools violate equal protection?
Held: Yes. Separate educational facilities are inherently unequal.
Ratio: State-imposed public school segregation violates the Equal Protection Clause.

constitutional law

education law

civil rights law

Gideon v. Wainwright

criminal law and procedure

372 U.S. 335 (1963)

Supreme Court of the United States · 1963 · United States

Issue: Does the Sixth Amendment right to counsel apply to state felony prosecutions?
Held: Yes. Indigent felony defendants must receive appointed counsel.
Ratio: States must provide counsel to indigent defendants charged with serious crimes.

criminal law and procedure

constitutional law

Miranda v. Arizona

criminal law and procedure

384 U.S. 436 (1966)

Supreme Court of the United States · 1966 · United States

Issue: What safeguards are required before custodial interrogation?
Held: Warnings are required to protect the Fifth Amendment privilege against self-incrimination.
Ratio: Before custodial interrogation, police must advise suspects of silence, counsel, and waiver rights.

criminal law and procedure

constitutional law

Mapp v. Ohio

criminal law and procedure

367 U.S. 643 (1961)

Supreme Court of the United States · 1961 · United States

Issue: Does the exclusionary rule apply to the states?
Held: Yes. Unconstitutionally obtained evidence is inadmissible in state criminal trials.
Ratio: Evidence obtained in violation of the Fourth Amendment is generally excluded in state and federal prosecutions.

criminal law and procedure

evidence law

Terry v. Ohio

criminal law and procedure

392 U.S. 1 (1968)

Supreme Court of the United States · 1968 · United States

Issue: Can police conduct a brief stop and frisk on less than probable cause?
Held: Yes, if supported by reasonable suspicion and limited to officer safety.
Ratio: A Terry stop requires reasonable suspicion; a frisk requires reasonable suspicion that the person is armed and dangerous.

criminal law and procedure

constitutional law

Roe v. Wade

constitutional law

410 U.S. 113 (1973)

Supreme Court of the United States · 1973 · United States

Issue: Did the Constitution protect a right to choose abortion under the Due Process Clause?
Held: The Court recognized such a right; the holding was later overruled by Dobbs.
Ratio: Roe is no longer controlling federal constitutional law after Dobbs.

constitutional law

reproductive law

Dobbs v. Jackson Women's Health Organization

constitutional law

597 U.S. 215 (2022)

Supreme Court of the United States · 2022 · United States

Issue: Does the Constitution confer a right to abortion?
Held: No. The Court overruled Roe and Casey.
Ratio: Abortion regulation is generally returned to democratic processes, subject to rational basis review federally.

constitutional law

reproductive law

Obergefell v. Hodges

constitutional law

576 U.S. 644 (2015)

Supreme Court of the United States · 2015 · United States

Issue: Do due process and equal protection protect same-sex marriage?
Held: Yes. Same-sex couples have a constitutional right to marry.
Ratio: States must license and recognize marriages between two people of the same sex.

constitutional law

family law

United States v. Lopez

constitutional law

514 U.S. 549 (1995)

Supreme Court of the United States · 1995 · United States

Issue: Was the statute a valid exercise of commerce power?
Held: No. The regulated conduct was not economic activity substantially affecting interstate commerce.
Ratio: Commerce power has judicially enforceable limits, especially for noneconomic local activity.

constitutional law

criminal law and procedure

Chevron U.S.A. Inc. v. Natural Resources Defense Council, Inc.

administrative law

467 U.S. 837 (1984)

Supreme Court of the United States · 1984 · United States

Issue: When should courts defer to an agency's interpretation of an ambiguous statute?
Held: The Court articulated a two-step deference framework; that framework was later overruled by Loper Bright.
Ratio: Chevron deference is no longer controlling after Loper Bright but remains historically important.

administrative law

environmental law

Erie Railroad Co. v. Tompkins

civil procedure

304 U.S. 64 (1938)

Supreme Court of the United States · 1938 · United States

Issue: May a federal court sitting in diversity apply federal general common law?
Held: No. Federal courts apply state substantive law in diversity cases.
Ratio: In diversity jurisdiction, federal courts apply state substantive law and federal procedural law.

civil procedure

federal courts law

International Shoe Co. v. Washington

civil procedure

326 U.S. 310 (1945)

Supreme Court of the United States · 1945 · United States

Issue: When may a state exercise personal jurisdiction over an out-of-state defendant?
Held: Jurisdiction was proper because the company had minimum contacts with Washington.
Ratio: Personal jurisdiction depends on minimum contacts and fairness.

civil procedure

constitutional law

Pennoyer v. Neff

civil procedure

95 U.S. 714 (1878)

Supreme Court of the United States · 1878 · United States

Issue: Could a state court bind an out-of-state defendant without personal service or attached property?
Held: No. The judgment was invalid for lack of jurisdiction.
Ratio: Traditional jurisdiction required presence, consent, domicile, or property control.

civil procedure

property law

Bell Atlantic Corp. v. Twombly

civil procedure

550 U.S. 544 (2007)

Supreme Court of the United States · 2007 · United States

Issue: What factual showing is required to survive a motion to dismiss?
Held: A complaint must plead enough facts to state a plausible claim.
Ratio: Federal pleadings must cross the line from conceivable to plausible.

civil procedure

antitrust law

Ashcroft v. Iqbal

civil procedure

556 U.S. 662 (2009)

Supreme Court of the United States · 2009 · United States

Issue: How should courts apply plausibility pleading to discrimination claims?
Held: The complaint did not plausibly plead purposeful discrimination by the named officials.
Ratio: Plausibility pleading applies across civil actions under the Federal Rules.

civil procedure

constitutional law

Daubert v. Merrell Dow Pharmaceuticals, Inc.

evidence law

509 U.S. 579 (1993)

Supreme Court of the United States · 1993 · United States

Issue: What standard governs admissibility of scientific expert testimony under Rule 702?
Held: Trial judges must act as gatekeepers for reliable, relevant expert testimony.
Ratio: Expert testimony must be reliable and fit the issues in the case.

evidence law

forensic evidence law

Crawford v. Washington

evidence law

541 U.S. 36 (2004)

Supreme Court of the United States · 2004 · United States

Issue: When does admission of testimonial hearsay violate the Confrontation Clause?
Held: Testimonial statements require unavailability and a prior opportunity for cross-examination.
Ratio: Testimonial hearsay is barred unless the witness is unavailable and previously subject to cross-examination.

evidence law

criminal law and procedure

Hadley v. Baxendale

contract law

9 Exch. 341, 156 Eng. Rep. 145 (1854)

Court of Exchequer · 1854 · England and Wales

Issue: Which consequential damages are recoverable for breach of contract?
Held: Only losses arising naturally or within the parties' contemplation are recoverable.
Ratio: Consequential damages require foreseeability at the time of contracting.

contract law

remedies law

Carlill v. Carbolic Smoke Ball Co.

contract law

[1893] 1 QB 256

Court of Appeal of England and Wales · 1893 · England and Wales

Issue: Was the advertisement an enforceable unilateral offer?
Held: Yes. The ad was a unilateral offer accepted by performance.
Ratio: A clear reward advertisement can create a unilateral contract accepted by performance.

contract law

consumer protection law

Donoghue v. Stevenson

tort law

[1932] AC 562

House of Lords · 1932 · United Kingdom

Issue: Did a manufacturer owe a duty of care to an ultimate consumer without privity?
Held: Yes. A manufacturer can owe a duty to foreseeable consumers.
Ratio: A person must take reasonable care to avoid acts likely to injure closely and directly affected neighbors.

tort law

consumer protection law

Palsgraf v. Long Island Railroad Co.

tort law

248 N.Y. 339 (1928)

New York Court of Appeals · 1928 · New York, United States

Issue: Was the railroad liable to an unforeseeable plaintiff?
Held: No. The risk to Palsgraf was not reasonably foreseeable.
Ratio: Negligence liability requires a duty to the plaintiff based on foreseeable risk.

tort law

MacPherson v. Buick Motor Co.

tort law

217 N.Y. 382 (1916)

New York Court of Appeals · 1916 · New York, United States

Issue: Could the manufacturer owe a duty without contractual privity?
Held: Yes. Manufacturers owe duties for products likely to be dangerous if negligently made.
Ratio: Manufacturers can owe negligence duties to foreseeable users of dangerous products.

tort law

consumer protection law

Pierson v. Post

property law

3 Cai. R. 175 (N.Y. Sup. Ct. 1805)

Supreme Court of Judicature of New York · 1805 · New York, United States

Issue: Does pursuit alone create property rights in a wild animal?
Held: No. Occupancy required capture or mortal wounding.
Ratio: Property in wild animals generally requires actual possession or certain control.

property law

Moore v. Regents of the University of California

property law

51 Cal. 3d 120 (1990)

Supreme Court of California · 1990 · California, United States

Issue: Did the patient retain property rights in excised cells?
Held: No conversion claim, but fiduciary duty and informed consent claims could proceed.
Ratio: Patients may have disclosure-based claims even when conversion does not apply to excised cells.

property law

bioethics law

health law

Raffles v. Wichelhaus

contract law

2 H. & C. 906, 159 Eng. Rep. 375 (Ex. 1864)

Court of Exchequer · 1864 · England and Wales

Issue: Was there mutual assent when the parties meant different ships?
Held: No enforceable contract was found on the pleaded ambiguity.
Ratio: Mutual misunderstanding about a material term can prevent contract formation.

contract law

Lucy v. Zehmer

contract law

196 Va. 493 (1954)

Supreme Court of Virginia · 1954 · Virginia, United States

Issue: Does objective manifestation of assent control over undisclosed intent?
Held: Yes. The written agreement was enforceable.
Ratio: Contract assent is measured objectively by outward expression.

contract law

property law

Hamer v. Sidway

contract law

124 N.Y. 538 (1891)

New York Court of Appeals · 1891 · New York, United States

Issue: Was forbearance from legal rights valid consideration?
Held: Yes. The nephew's forbearance was sufficient consideration.
Ratio: Forbearance from a legal right can be valid consideration.

contract law

Hawkins v. McGee

contract law

84 N.H. 114 (1929)

Supreme Court of New Hampshire · 1929 · New Hampshire, United States

Issue: How should damages be measured for breach of a promised surgical result?
Held: Expectation damages measured the difference between promised and actual result.
Ratio: Expectation damages place the plaintiff in the position performance would have produced.

contract law

remedies law

Kelo v. City of New London

property law

545 U.S. 469 (2005)

Supreme Court of the United States · 2005 · United States

Issue: Can economic development qualify as public use under the Fifth Amendment?
Held: Yes, under the deferential public purpose approach.
Ratio: Public use includes public purpose under federal takings doctrine.

property law

constitutional law

Lucas v. South Carolina Coastal Council

property law

505 U.S. 1003 (1992)

Supreme Court of the United States · 1992 · United States

Issue: When does a regulation become a categorical taking?
Held: A regulation denying all economically beneficial use generally requires compensation.
Ratio: Total economic wipeouts are categorical takings subject to narrow exceptions.

property law

environmental law

Penn Central Transportation Co. v. New York City

property law

438 U.S. 104 (1978)

Supreme Court of the United States · 1978 · United States

Issue: Did the landmark law effect a regulatory taking?
Held: No. The regulation did not go too far under an ad hoc balancing approach.
Ratio: Regulatory takings are often assessed by economic impact, expectations, and character of government action.

property law

land use law

National Federation of Independent Business v. Sebelius

constitutional law

567 U.S. 519 (2012)

Supreme Court of the United States · 2012 · United States

Issue: Could Congress enact the mandate and Medicaid expansion under enumerated powers?
Held: The mandate was sustained as a tax; the Medicaid expansion remedy was limited.
Ratio: Congress may tax conduct but may not coerce states through unduly punitive spending conditions.

constitutional law

health law

Citizens United v. Federal Election Commission

constitutional law

558 U.S. 310 (2010)

Supreme Court of the United States · 2010 · United States

Issue: May government restrict independent political expenditures by corporations?
Held: No. Such restrictions violated the First Amendment.
Ratio: Independent political expenditures receive strong First Amendment protection.

constitutional law

election law

New York Times Co. v. Sullivan

defamation law

376 U.S. 254 (1964)

Supreme Court of the United States · 1964 · United States

Issue: What constitutional fault standard applies to public official defamation claims?
Held: Public officials must prove actual malice.
Ratio: Public officials must show knowing falsity or reckless disregard for truth.

defamation law

first amendment law

Tinker v. Des Moines Independent Community School District

first amendment law

393 U.S. 503 (1969)

Supreme Court of the United States · 1969 · United States

Issue: Do students retain First Amendment rights at school?
Held: Yes, absent material and substantial disruption.
Ratio: Schools may restrict student speech only when it materially and substantially disrupts school operations or invades rights of others.

first amendment law

education law

R v. Dudley and Stephens

criminal law and procedure

14 QBD 273 (1884)

Queen's Bench Division · 1884 · England and Wales

Issue: Is necessity a defense to murder?
Held: No. Necessity was not a defense to intentional murder on these facts.
Ratio: Necessity generally does not excuse intentional killing of an innocent person.

criminal law and procedure

R v. R

criminal law and procedure

[1991] UKHL 12, [1992] 1 AC 599

House of Lords · 1991 · United Kingdom

Issue: Did a marital rape exemption remain part of common law?
Held: No. The exemption was no longer recognized.
Ratio: A spouse can be criminally liable for rape of the other spouse.

criminal law and procedure

family law

Airedale NHS Trust v. Bland

bioethics law

[1993] AC 789

House of Lords · 1993 · United Kingdom

Issue: Could treatment be lawfully withdrawn when continuation was not in the patient's best interests?
Held: Yes, with court approval on the facts.
Ratio: Life-sustaining treatment may be withdrawn where it is not in the patient's best interests, subject to legal safeguards.

bioethics law

health law

Salomon v. A Salomon & Co Ltd

business associations law

[1897] AC 22

House of Lords · 1897 · United Kingdom

Issue: Was the company a separate legal person from its shareholder?
Held: Yes. Properly incorporated companies have separate legal personality.
Ratio: A corporation is a separate legal person from its shareholders.

business associations law

corporate law

Foss v. Harbottle

business associations law

(1843) 2 Hare 461, 67 ER 189

Court of Chancery · 1843 · England and Wales

Issue: Who is the proper plaintiff for wrongs done to a company?
Held: The company is generally the proper plaintiff.
Ratio: Wrongs to a company are ordinarily enforced by the company, subject to exceptions.

business associations law

corporate law

Central London Property Trust Ltd v. High Trees House Ltd

contract law

[1947] KB 130

King's Bench Division · 1947 · England and Wales

Issue: Could a promise to accept less be enforced despite lack of consideration?
Held: The landlord could not recover wartime arrears for the reduced-rent period.
Ratio: A clear promise intended to be binding and relied upon may be enforceable as a shield through promissory estoppel.

contract law

equity law

Entores Ltd v. Miles Far East Corp.

contract law

[1955] 2 QB 327

Court of Appeal of England and Wales · 1955 · England and Wales

Issue: Where and when is acceptance effective for instantaneous communication?
Held: Acceptance was effective when received by the offeror.
Ratio: For instantaneous communications, acceptance generally occurs on receipt.

contract law

e commerce law

Caparo Industries plc v. Dickman

tort law

[1990] 2 AC 605

House of Lords · 1990 · United Kingdom

Issue: When does a duty of care arise for negligent misstatement?
Held: No duty was owed to investors for the takeover purpose.
Ratio: The Caparo test asks foreseeability, proximity, and fairness for novel duty situations.

tort law

professional responsibility law

Rylands v. Fletcher

tort law

(1868) LR 3 HL 330

House of Lords · 1868 · United Kingdom

Issue: Can liability attach without negligence for escape of dangerous things?
Held: Yes, under the rule for non-natural use and escape.
Ratio: Strict liability may apply for escape of dangerous things from non-natural land use.

tort law

environmental law

Bush v. Gore

election law

531 U.S. 98 (2000)

Supreme Court of the United States · 2000 · United States

Issue: Did the recount procedures violate equal protection?
Held: Yes, the recount as ordered violated equal protection and could not be completed in time.
Ratio: Election recount procedures must satisfy equal protection constraints.

election law

constitutional law

Mabo v Queensland (No 2)

advanced

(1992) 175 CLR 1

High Court of Australia · 1992 · Australia

Issue: Whether the common law doctrine of terra nullius applied in Australia and whether indigenous native title could survive the Crown's acquisition of sovereignty.
Held: The common law of Australia recognises a form of native title that reflects the entitlement of indigenous inhabitants to their traditional lands. The doctrine of terra nullius was wrongly applied.
Ratio: Native title is recognised at common law when the claimants can demonstrate a continuous connection to the land under traditional laws and customs, and the title has not been extinguished by a valid legislative or executive act.

African Customary Law

Indigenous Legal Systems

Constitutional Law

Hedley Byrne & Co Ltd v Heller & Partners Ltd

intermediate

[1964] AC 465

House of Lords · 1964 · United Kingdom

Issue: Whether a duty of care can arise for purely economic loss caused by a negligent misstatement even in the absence of a contractual relationship.
Held: A duty of care may arise when one party voluntarily assumes responsibility to give information or advice to another, and the other reasonably relies on it, but the disclaimer in this case negated liability.
Ratio: A duty of care in respect of pure economic loss may be established where (1) there is a special relationship based on an assumption of responsibility, (2) the claimant reasonably relies on the statement, and (3) the loss is a foreseeable consequence of negligence.

Agricultural Law

Banking Law

Commercial Law