The United States has five permanent territories. PUERTO RICO, in the Caribbean, and Guam, in the Western Pacific, were acquired as a result of the Spanish-American War in 1899. American Samoa, the only U.S. TERRITORY south of the equator, was ceded to the United States by the matai (the chiefs) of the islands in 1900 and 1904. The U.S. Virgin Islands, in the Caribbean east of Puerto Rico, were purchased from Denmark in 1917. The people of what is now the Commonwealth of the Northern Mariana Islands (CNMI), formerly a part of the Trust Territory of the Pacific Islands, voted in a 1976 plebiscite to become a part of the United States. Residents of each of the territories, except American Samoa, enjoy United States CITIZENSHIP at birth. Residents of American Samoa are United States nationals at birth, and may obtain immediate United States citizenship upon establishing a domicile in a U.S. state (which they, along with other territorials, have an absolute right to do). Official and unofficial REFERENDA indicate that large majorities in each of the territories favor continued affiliation with the United States.
The United States has had territories from its inception. The Northwest Territory was a part of the nation when the Constitution was ratified. That the Framers of the Constitution contemplated the existence of nonstate territories is demonstrated by Article IV, Section 3, Clause 2, commonly called the "territorial clause." It provides, "The Congress Shall have Power to dispose of and make all needful Rules and Regulations respecting the Territory or other Property belonging to the United States."
In 1826, Chief Justice JOHN MARSHALL held, in American Insurance Co. v. 356 Bales of Cotton (David Canter, claimant), that Congress, acting under this clause, could treat territories differently from states and could create courts in territories that combine the functions of Article III federal courts and state courts.
So far as the rest of the Constitution is concerned, early cases seemed to follow the "ex proprio vigore" (by its own force) DOCTRINE, which was summed up in the phrase "the Constitution follows the flag." In the INSULAR CASES (1901) (especially Downes v. Bidwell), the Supreme Court moved toward the "incorporation doctrine," which was clearly accepted law by the time of Balzac v. Porto Rico (1922). Under the incorporation doctrine, the Constitution is not fully applicable in a territory unless that...