There are now about eighty District Courts, nine of which are in the territories. In a few instances two districts are assigned to one judge. For each district a United States district attorney is appointed to represent the interests of the Federal Government. Marshals and other court officers are also provided. District judges must reside within their respective districts. They may, when assigned by the circuit judge or justice or the Chief Justice of the Supreme Court, hold the District or Circuit Court for any disability to hold any federal office rests upon the judge. Thus Jay while Chief Justice was for a time Secretary of State, and also minister to England; Ellsworth while associate justice was minister to France; and Marshall while Chief Justice was for a time Secretary of State. 5 Rev. Stat., § 609.