At the head of the judicial system is the Supreme Court of nine judges, which sits at Washington. There are ten Circuit Courts of Appeal, each with at least three circuit judges, there being a total of 46 circuit judges, together with six judges of the United States Court of Appeals for the District of Columbia. To each circuit is assigned a justice of the United States Supreme Court, one of the justices now being assigned to two circuits. The pressure of busi ness in the United States Supreme Court has, however, now made it impossible for the judges of the Supreme Court to go on circuit. The District Court is the court of original jurisdiction. In erecting dis tricts for the organization of this court, State lines are regarded. The smaller States constitute single districts ; the larger are divided. For the districts in which Federal judicial business is especially heavy, more than one district judge is provided. For example, four districts with 18 judges exist in New York. There are more than 8o districts, with 146 judges, and the number of judges constantly increases. In addition to the general system of courts here outlined, there are a Court of Claims, Court of Customs and Patent Appeals, and Federal Courts for the District of Columbia and the Territories.
With the two systems of courts—Federal and State—exercising jurisdiction over the same territory, it is necessary that there be cer tain principles as to their relationship. Such principles may be briefly summarized as follows: (I) Upon questions of Federal constitutional law, the United States Supreme Court is the final court of review. If the highest court of a State holds a Federal statute or treaty to be invalid, or a State statute valid that is alleged to violate the Federal Con stitution or Federal statutes, the losing party has a right to a final decision by the highest Federal Court. Where Federal constitu tional issues are otherwise involved in State courts, the United States Supreme Court, may, in its discretion, review the State decision.
(2) All cases involving the enforcement of the criminal law of the Federal Government are tried in the Federal Courts.
(3) Cases of admiralty and maritime jurisdiction and bank ruptcy proceedings are tried in the Federal Courts.
(4) Under Federal statutes, the Federal Courts alone have jur isdiction of suits against the United States, and of suits for the enforcement of Federal revenue, immigration and other similar laws directly affecting the administration of the Federal Govern ment.
(5) In civil cases involving as much as $3,000, and (a) arising between citizens of different States or (b) arising under the con stitution, laws or treaties of the United States, the parties have the choice of suing either in State or Federal Courts ; but if the plaintiff sues in the State Court, the defendant may transfer the case to the Federal Court.
(6) By statute it is provided "that the laws of the several States, except where the Constitution, treaties or statutes of the United States otherwise require or provide, shall be regarded as rules of decision in trials at common law, in the courts of the United States, in cases where they apply." By recent decisions of the United States Supreme Court, the Federal Courts must apply not only State statutes but also the law as found in the decisions of the State Courts. Until the adoption of uniform rules of civil procedure for United States District Courts in 1937, the procedure in such courts in cases at common law was re quired to conform, as near as may be, with the procedure "in like causes in the courts of record of the State within which such district courts are held." Through legislation of 1925 an effort has been made to reduce the number of cases that must be decided by the United States Supreme Court. That court has a limited original jurisdiction, the most impor tant cases of such jurisdiction being cases to which a State is a party. Cases not infrequently arise in which one State sues another State. Aside from its original jurisdiction, cases come to the United States Supreme Court either from the highest State Courts or from the lower Federal Courts. The decisions of the United States Supreme Court are of primary importance in the fields of constitutional and public law.