President for each district court.  The United States district attorney is required to prosecute all persons accused of the violation of Federal law and to appear as defendant in cases brought against the government of the United States in his district.  The United States marshal executes the warrants or other orders of the United States district court, and, in general, performs duties connected with the enforcement of the Federal laws which resemble the duties of sheriffs under State laws.

Circuit Courts and Courts of Appeals.—­Established by the act of 1789, each circuit court was at first presided over by a justice of the Supreme Court and a district judge.  The policy was to have as many circuit courts as there were justices of the Supreme Court.  It was not until 1869 that a circuit judge was provided for each of the nine circuits.  By an Act of Congress during the year 1911, in response to the agitation for a simplified Federal judicial system and greater expedition in the hearing of cases, the circuit courts were abandoned.  Judges of these courts were transferred to the circuit courts of appeals.  The circuit courts of appeals consist of three judges each, any two constituting a quorum.  Supreme Court judges and district judges may sit in these courts.  The Court of Claims was established in 1855 and consists of a chief justice and four associates.  It holds an annual session in Washington.

Terms and Salaries of the Judges.—­That the judiciary should be independent of parties and of other influences cannot be questioned.  Hence the wisdom of the provision that United States judges shall hold their offices during good behavior and shall receive a compensation for their services which shall not be diminished during their continuance in office.  Judges of the United States courts are appointed by the President with the consent of the Senate.

By an Act of Congress of 1911 the salary of the Chief Justice was fixed at $15,000 per annum; that of associate justices, $14,500; and district judges, $6000.

Jurisdiction of the National Courts.—­We are next to consider the jurisdiction of the several courts that have been described.

Section 2, Clause 1. The judicial power shall extend to all cases, in law and equity, arising under this Constitution, the laws of the United States, and treaties made, or which shall be made, under their authority;—­to all cases affecting ambassadors, other public ministers and consuls;—­to all cases of admiralty and maritime jurisdiction;—­to controversies to which the United States shall be a party;—­to controversies between two or more States;—­between a State and citizens of another State;—­between citizens of different States;—­between citizens of the same State claiming lands under grants of different States, and between a State, or the citizens thereof, and foreign states, citizens or subjects.  A careful consideration of this clause shows the wide extent of the powers of the United States courts.