4 U.S. Code § 71
4 U.S. Code § 71 is about Permanent seat of Government. It is under Chapter 3 (Seat Of The Government) of Title 4 (Flag And Seal, Seat Of Government, And The States) of the Code.
All that part of the territory of the United States included within the present limits of the District of Columbia shall be the permanent seat of government of the United States.