From one to 27 judges sit in each of the district courts. Depending on case load, a judge from one district may temporarily sit in another district. Congress fixes the boundaries of the districts according to population, size and volume of work. Some of the smaller states constitute a district by themselves, while the larger states, such as New York, California and Texas, have four districts each. Except in the District of Columbia, judges must be residents of the district in which they permanently serve.
District courts hold their sessions at periodic intervals in different cities of the district.
Most cases and controversies heard by these courts involve federal offenses such as misuse of the mails, theft of federal property, and violations of pure food, banking and counterfeiting laws. These are the only federal courts where grand juries indict those accused of crimes, and juries decide the cases. I n addition to the federal courts of general jurisdiction, it has been necessary from time to time to set up courts for special purposes. Judges in these courts, like their peers in other federal courts, are appointed for life terms by the president, with Senate approval. Perhaps the most important of these special courts is the Court of Claims, established in 1855 to render judgment on monetary claims against the United States.