Judicial Branch
Learn how federal courts interpret law, resolve disputes, and review government action.
The judicial branch decides what federal law means and whether government action fits within the Constitution. Federal courts hear real cases involving national laws, constitutional rights, disputes between parties, and challenges to actions by Congress, the President, or federal agencies.
It is emphatically the province and duty of the judicial department to say what the law is.
Chief Justice John Marshall, Marbury v. Madison
Explore the Judicial Branch
Court Structure
- Federal CourtsHow district courts, appeals courts, and the Supreme Court fit together.
- District CourtsTrial courts where federal cases begin and facts are developed.
- Courts of AppealsPanels that review legal errors in lower-court decisions.
- Supreme CourtFinal authority on federal and constitutional law.
Judicial Power
- Judicial ReviewHow courts assess laws and government action under the Constitution.
- PrecedentWhy earlier decisions guide later cases and when they can change.
- Federal JurisdictionWhich cases belong in federal court and why jurisdiction matters.
- Types of CasesConstitutional, civil, criminal, administrative, and rights cases.
Supreme Court
- How Cases Reach ItPetitions, certiorari, the rule of four, and limited review.
- Oral ArgumentsHow justices question lawyers and test legal arguments.
- Opinions and DissentsMajority opinions, concurrences, dissents, and legal reasoning.
- Landmark CasesMajor decisions that shaped constitutional law and public life.
Judges & Resources
Article III
The federal courts.
The Constitution creates the Supreme Court and gives Congress power to establish lower federal courts. Federal judges decide real cases and controversies, explain what the law means, and review government action under the Constitution and federal law.
How a Federal Case Moves
Most federal cases begin in district court, move to an appeals court only if a party challenges the result, and reach the Supreme Court only in rare circumstances. Each stage asks a different question about facts, legal error, and national legal meaning.
Filing a Case
A party files a complaint or the government brings charges in the appropriate federal court.
District Court
Evidence is presented, facts are developed, and a judge or jury enters a first decision.
Appeal
A panel reviews the record to decide whether the lower court made a legal error.
Certiorari
A party may petition the Supreme Court; four justices must vote to hear the case.
Oral Argument
Lawyers answer the justices’ questions about legal text, precedent, and consequences.
Opinion and Precedent
The Court explains its ruling in writing, giving lower courts a rule to apply.
The Federal Court System
District Courts
Federal trial courts hear evidence, manage cases, and decide disputes. They are the usual starting point for federal civil suits, criminal prosecutions, and constitutional challenges.
Courts of Appeals
Federal appellate courts review trial-court records and briefs to determine whether the law was applied correctly. They generally do not retry facts or hear new evidence.
Supreme Court
The Court has final authority on federal and constitutional questions. It chooses a small share of petitions and issues opinions that guide lower courts nationwide.
The judicial Power of the United States, shall be vested in one supreme Court, and in such inferior Courts as the Congress may from time to time ordain and establish.
U.S. Constitution, Article III
Judicial Review
Judicial review allows courts to decide whether laws, regulations, and executive actions comply with the Constitution and federal statutes. It connects individual disputes to limits on public power.
Landmark Cases
Use the Landmark Cases archive to explore major decisions by legal question, holding, constitutional topic, historical context, and lasting impact—not as a static list on this branch home page.