Map of the boundaries of the United States courts of appeals
(by color) and United States District Courts. All District Courts lie within the boundary of a single jurisdiction, usually in a state
(heavier lines); some states have more than one District Court (lighter lines denote those jurisdictions)
The United States district courts are the general trial courts of the United States federal court system. Both civil and criminal cases are filed in the district court, which is a court of law, equity, and admiralty. There is a United States bankruptcy court associated with each United States district court. Each federal judicial district has at least one courthouse, and many districts have more than one. The formal name of a district court is "the United States District Court for" the name of the district—for example, the United States District Court for the Eastern District of Missouri.
In contrast to the Supreme Court, which was established by Article III of the Constitution, the district courts were established by Congress.[note 1] There is no constitutional requirement that district courts exist at all. Indeed, after the ratification of the Constitution, some opponents of a strong federal judiciary urged that, outside jurisdictions under direct federal control, like Washington, D.C., and the territories, the federal court system be limited to the Supreme Court, which would hear appeals from state courts. This view did not prevail, however, and the first Congress created the district court system that is still in place today.
There is at least one judicial district for each state, the District of Columbia, and Puerto Rico. The territories (insular areas) of Guam, the Northern Mariana Islands, and the United States Virgin Islands each have one territorial court; these courts are called "district courts" and exercise the same jurisdiction as district courts, but differ from district courts in that territorial courts are Article IV courts, with judges who serve ten-year terms rather than the lifetime tenure of judges of Article III courts, such as the district court judges. American Samoa does not have a district court or a federal territorial court, and so federal matters there are sent to either the District of Columbia or Hawaii.
There are 89 districts in the 50 states, with a total of 94 districts including territories.