The district courts and circuit courts, as above described, exercise only original and not appellate jurisdiction. The courts of these two classes, together with the Supreme* Court, constituted the judicial department of the federal government until 1891, when a new court was created, called the circuit court of appeals, to be held at one or more places in each circuit, presided over by the three judges authorized to hold the circuit courts throughout the circuit, that is, the justice of the Supreme Court assigned to the circuit, and the two circuit judges appointed for the circuit. But by acts of Congress passed from time to time the number of circuit judges in many of the circuits has been increased to three, and in practice the justices of the Supreme Court do not, except in rare instances, serve in this capacity. Where there are only two circuit judges, or in case one or more of the circuit judges is incapacitated to sit, the requisite number of judges is provided by assigning district judges from districts within the circuit to serve temporarily. In no instance does the judge who has tried a case sit in the circuit court of appeals on the hearing of an appeal in such case.

Before the creation of the circuit courts of appeals, the appellate jurisdiction over the district and circuit courts was exercised exclusively by the Supreme Court, save that as to a few classes of cases appeals might be taken from the district to the circuit courts. When the circuit courts of appeals were established, the appellate jurisdiction of the circuit courts was transferred to them, and they were given also a considerable portion of the appellate jurisdiction formerly exercised by the Supreme Court, the object of establishing the circuit courts of appeals being to relieve the Supreme Court of some of the business with which it was found to be overburdened.

The circuit courts of appeals have in general jurisdiction to hear appeals from the district and circuit courts in suits which are between citizens of different states, or citizens of a state and aliens; also in admiralty cases and cases under the patent, copyright, revenue, or postal laws, and in criminal cases where the crime is not capital or otherwise infamous, in which case the appeal is to the Supreme Court. With few exceptions the decision of a circuit court of appeals, in a case properly appealed to it, is conclusive, and no further appeal to the Supreme Court of the United States can be taken. The circuit courts of appeals do not entertain appeals from state or territorial courts, but only from the district and circuit courts. But an exception is made in case of the United States court in the Indian Territory, which is put on the same basis as the district and circuit courts.