There are 94 federal judicial districts in the United States, and each has one district court. These are the trial courts of the federal system, the place where a federal lawsuit or prosecution starts.
The count breaks down simply. The 50 states hold 89 districts, with at least one each for every state, the District of Columbia and Puerto Rico. Guam, the Northern Mariana Islands and the U.S. Virgin Islands each have a territorial court that also carries the district court label, which brings the total to 94. A state has between one and four districts, and those with several are named by compass point. New York and Texas use all four directions. California has a Central District but no Western one. Illinois has a Central District in place of a Middle one.
Where they came from
The Constitution created the Supreme Court. It left the lower courts to Congress, which built the district system through the Judiciary Act of 1789. Nothing in the Constitution requires that district courts exist at all.
Some opponents of a strong federal judiciary had argued during ratification that the Supreme Court should sit alone, hearing appeals from state courts, with state judges deciding federal questions. Edward Carrington made that case in a letter to James Madison, and Alexander Hamilton took it up in Federalist No. 81. The first Congress went the other way. It created 13 districts among the 11 states that had ratified by then, then added one each for North Carolina and Rhode Island, for 15.
What they hear
District courts handle civil and criminal cases, and their reach is limited. They can take disputes between citizens of different states, questions of federal law and federal crimes. They are also the only federal trial courts with jurisdiction over civilian criminal cases. Specialized courts exist for narrower work: the Court of International Trade covers trade and customs, and the Court of Federal Claims handles most money-damages claims against the federal government.
For many of these cases a plaintiff can choose between federal and state court, because state courts keep concurrent jurisdiction over most federal matters. A defendant sued in state court can move the case to federal court if it could have been filed there originally. Patent and copyright disputes and federal prosecutions are different. Only federal courts can hear them.
Rulings go up to the court of appeals for the circuit where the district sits. A few specialized cases go to the Federal Circuit or straight to the Supreme Court.
Judges
District judges outside the three territories hold lifetime appointments under Article III. In the Virgin Islands, Guam and the Northern Mariana Islands, judges serve 10-year terms. Magistrate judges, appointed by each district court for eight-year terms, also work trials and hearings. The district court system has no seat for American Samoa, so its federal cases go to the District of Columbia or Hawaii.
