The jurisdiction of the federal courts has been defined by the Constitution, congressional statutes, and decisions of the Supreme Court of the United States. Article III provides that the judicial power "shall extend" to nine types of "cases" and "controversies": all cases in law and equity arising under the Constitution, laws, and treaties of the United States; all cases affecting ambassadors, other public ministers and consuls; all cases of admiralty and maritime jurisdiction; controversies to which the United States is a party; controversies between two or more states; controversies between a state and citizens of another state; controversies between citizens of different states; controversies between citizens of the same state claiming lands under grants of different states; and controversies between a state or its citizens and foreign states, citizens, or subjects. The Constitution grants the Supreme Court original jurisdiction over cases affecting ambassadors and public ministers and cases in which a state is a party, leaving the remainder of cases within the judicial power to the Court's appellate jurisdiction, with "such exceptions, and under such regulations as the Congress shall make."
Article III of the Constitution left for the Congress to determine the distribution of federal jurisdiction within a system of federal courts and between the federal and state courts. The Judiciary Act of 1789 provided for cases to enter a federal court through an original filing, through removal of a case originally filed in state court, and through an appeal from the highest court of a state to the Supreme Court of the United States. Over the past two centuries, Congress has passed numerous statutes redefining the jurisdiction of the federal courts within the limits set by the Constitution. Throughout its history, the Supreme Court in its decisions has established additional rules and doctrines governing federal court jurisdiction.