Decides what federal law means, and whether government action fits within the Constitution.
The judicial branch runs on a three-tier structure: district courts where cases begin and facts get developed, appeals courts that review legal errors, and the Supreme Court as the final authority on federal and constitutional questions.
It is emphatically the province and duty of the judicial department to say what the law is.
Chief Justice John Marshall
Court Structure
District courts
The trial courts where federal cases begin and the factual record gets developed.
Appeals courts
Panels that review legal errors from lower court decisions, generally without retrying facts.
Supreme Court
The final authority for questions of federal and constitutional law.
Explore the Judicial Branch
Federal JudgesNomination, confirmation, and lifetime tenure.→
Judicial ReviewThe power to decide whether government action is lawful.→
Landmark CasesThe decisions that changed how courts read the Constitution.→
Most federal cases never reach the Supreme Court at all
A common misconception is that “going to court” over a federal issue eventually means the Supreme Court weighing in. In reality, the overwhelming majority of federal cases are resolved at the district or appeals court level — the Supreme Court hears only a small, carefully chosen fraction of cases each year, out of thousands of petitions filed.
