Bouvier's Law dictionary states the following:
A part of a country separate from the rest and subject to the particular jurisdiction. A portion of the country subject to and belonging to the United States which is not within the boundary of any state or the District of Columbia.
"The territories of the United States are entirely subject to the legislative authority of Congress. They are not organized under the Constitution, nor subject to the complex distribution of powers of government as the organic law, but are the creation, exclusively, of the legislative department, and subject to his supervision and control. … It [Congress] may legislate in accordance with special needs of each locality, and various regulations to meet the conditions
and circumstances of the people.
… In a territory all the functions of government are within the legislative jurisdiction of Congress, and may be exercised through local government or directly;" Endlman v. US., 86 Fed 456, 30 C.C.A. 186, citing Cross v. Harrison, 16 How. (U.S.) 164, 14 L. Ed. 889; Shively v. Bowlby, 152 U. S. 1, 14 Sup. Ct. 548, 28 L. Ed. 331