Under United States law, an unincorporated territory is an area controlled by the United States government which is not part of (i.e., "incorporated" in) the United States. In unincorporated territories, the U.S. Constitution applies only partially. In the absence of an organic law, a territory is classified as unorganized. In unincorporated territories, "fundamental rights apply as a matter of law, but other constitutional rights are not available".  Selected constitutional provisions apply depending on congressional acts and judicial rulings according to U.S. constitutional practice, local tradition, and law.
There are currently 13 unincorporated territories, comprising a land area of approximately 12,000 square kilometers (4,600 square miles) containing a population of approximately 4 million people; Puerto Rico alone comprises the vast majority of both the total area and total population.
Of the 13 territories, five are inhabited. These are either organized or self-governing,  but unincorporated. These are Puerto Rico, Guam, Northern Mariana Islands, U.S. Virgin Islands, and American Samoa.  There are also nine uninhabited US possessions, of which only Palmyra Atoll is incorporated. (See Territories of the United States, Unorganized territory  and insular area.)
All modern inhabited territories under the control of the federal government can be considered as part of the "United States" for purposes of law as defined in specific legislation.  However, the judicial term "unincorporated" was coined to legitimize the U.S. late 19th-century territorial acquisitions without citizenship and their administration without constitutional protections temporarily until Congress made other provisions. The case law allowed Congress to impose discriminatory tax regimes with the effect of a protective tariff upon territorial regions which were not domestic states. 
From 1901 to 1905, the U.S. Supreme Court, in a series of opinions known as the Insular Cases, held that the Constitution extended ex proprio vigore (i.e., of its own force) to the continental territories. However, the Court in these cases also established the doctrine of territorial incorporation, under which the Constitution applies fully only in incorporated territories such as Alaska and Hawaii, and applies only partially in the new unincorporated territories of Puerto Rico, Guam and the Philippines.  
The United States District Court is not a true United States court established under article 3 of the Constitution to administer the judicial power of the United States therein conveyed. It is created by virtue of the sovereign congressional faculty, granted under article 4, 3, of that instrument, of making all needful rules and regulations respecting the territory belonging to the United States. The resemblance of its jurisdiction to that of true United States courts, in offering an opportunity to nonresidents of resorting to a tribunal not subject to local influence, does not change its character as a mere territorial court. 
Upon like considerations, Article III has been viewed as inapplicable to courts created in unincorporated territories outside the mainland, Downes v. Bidwell, 182 U.S. 244, 266–267; Balzac v. Porto Rico, 258 U.S. 298, 312–313; cf. Dorr v. United States, 195 U.S. 138, 145, 149, and to the consular courts established by concessions from foreign countries, In re Ross, 140 U.S. 453, 464–465, 480. 18
"The inhabitants of the ceded territory ... shall be admitted to the enjoyment of all the rights, advantages, and immunities of citizens of the United States;"  "This declaration, although somewhat changed in phraseology, is the equivalent, as pointed out in Downes v. Bidwell, of the formula, employed from the beginning to express the purpose to incorporate acquired territory into the United States, especially in the absence of other provisions showing an intention to the contrary." 
|Territory||Population||Area (km2)||Area (sq mi)||Region|
|American Samoa ||55,519||197.1 km2||75.1 sq mi||Pacific|
|Guam||159,358 ||541.3 km2||209.0 sq mi||Pacific|
|Northern Mariana Islands||53,883||463.63 km2||179.01 sq mi||Pacific|
|Puerto Rico ||3,474,182||9,104 km2||3,515 sq mi||Caribbean|
|United States Virgin Islands||109,750||346.36 km2||133.73 sq mi||Caribbean|
|Baker Island||Uninhabited||2.1 km2||0.8 sq mi||Pacific|
|Howland Island||Uninhabited||1.8 km2||0.7 sq mi||Pacific|
|Jarvis Island||Uninhabited||4.5 km2||1.7 sq mi||Pacific|
|Johnston Atoll||Uninhabited||2.67 km2||1.03 sq mi||Pacific|
|Kingman Reef||Uninhabited||76 km2||29 sq mi||Pacific|
|Midway Atoll (administered as a National Wildlife Refuge)||Uninhabited||6.2 km2||2.4 sq mi||Pacific|
|Navassa Island (disputed with Haiti)||Uninhabited||5.2 km2||2.0 sq mi||Caribbean|
|Wake Island||150||7.38 km2||2.85 sq mi||Pacific|
|Total||4,085,200||12,272.24 km2||4,738.34 sq mi|
- Philippines – administered directly by the U.S. government 1898–1901; insular government 1901–1935; commonwealth 1935–1946; independent since July 4, 1946
- Panama Canal Zone – administered directly by the U.S. government 1903–1979; jointly administered with Panama 1979–1999; reverted to Panama beginning on December 31, 1999
- August 28, 1867
- Captain William Reynolds of the USS Lackawanna formally took possession of the Midway Atoll for the United States. 
- April 11, 1899
- The Treaty of Paris of 1898 came into effect, transferring Guam, the Philippines, and Puerto Rico from Spain to the United States, all three becoming unorganized, unincorporated territories. Puerto Rico's official name was changed to Porto Rico, a phonetic reinterpretation of the Spanish name for the territory.
- April 12, 1900
- The Foraker Act organized Puerto Rico. 
- June 7, 1900
- The United States took control of the portion of the Samoan Islands given to it by the Treaty of Berlin of 1899, creating the unorganized, unincorporated territory of American Samoa.
- April 1, 1901
- General Emilio Aguinaldo, the Filipino leader in the Philippine–American War and President of the Malolos Republic, surrendered to the United States, allowing the US to form a civilian government for the Philippines.
- February 23, 1903
- Under the terms of a 1903 lease agreement, the United States came to exercise complete control over Guantanamo Bay, Cuba, while Cuba retained ultimate sovereignty over the territory.
- August 29, 1916
- The Philippine Autonomy Act or Jones Law was signed, promising the Philippines independence.
- March 2, 1917
- Jones–Shafroth Act reorganized Puerto Rico. This act conferred United States citizenship on all citizens of Puerto Rico.
- March 31, 1917
- The United States purchased the U.S. Virgin Islands under the terms of a treaty with Denmark. 
- May 17, 1932
- The name of Porto Rico was changed to Puerto Rico. 
- March 24, 1934
- The Tydings–McDuffie Act was signed allowing the creation of the Commonwealth of the Philippines.
- July 4, 1946
- The United States recognized Philippine independence.
- July 14, 1947
- The United Nations granted the Trust Territory of the Pacific Islands to the United States, consisting primarily of many islands fought over during World War II, and including what is now the Marshall Islands, the Carolina Islands, Federated States of Micronesia, Northern Mariana Islands, and Palau. It was a trusteeship, and not a territory of the United States.
- August 5, 1947
- The Privileges and Immunities Clause regarding the rights, privileges, and immunities of citizens of the United States was expressly extended to Puerto Rico by the U.S. Congress through federal law codified in Title 48 the United States Code as 48 U.S.C. § 737 and signed by President Harry S. Truman. This law indicates that the rights, privileges, and immunities of citizens of the United States shall be respected in Puerto Rico to the same extent as though Puerto Rico were a State of the Union and subject to the provisions of paragraph 1 of section 2 of article IV of the Constitution of the United States.
- July 1, 1950
- The Guam Organic Act came into effect, organizing Guam as an unincorporated territory. 
- July 25, 1952
- Puerto Rico became a Commonwealth of the United States, an unincorporated organized territory, with the ratification of its constitution. 
- July 22, 1954
- The Organic Act for the United States Virgin Islands went into effect, making them an unincorporated, organized territory. 
- July 1, 1967
- American Samoa's constitution became effective. Even though no Organic Act was passed, this move to self-government made American Samoa similar to an organized territory. 
- September 12, 1967
- Article Three of the United States Constitution, was expressly extended to the United States District Court for the District of Puerto Rico by the U.S. Congress through the federal law 89-571, 80 Stat. 764, this law was signed by President Lyndon B. Johnson.
- January 1, 1978
- The Northern Mariana Islands left the Trust Territory of the Pacific Islands to become a commonwealth of the United States, making it unincorporated and organized.  
- October 21, 1986
- The Marshall Islands attained independence from the Trust Territory of the Pacific Islands, though the trusteeship granted by the United Nations technically did not end until December 22, 1990. The Marshall Islands remained in free association with the United States.
- November 3, 1986
- The Federated States of Micronesia attained independence from the Trust Territory of the Pacific Islands, and remained in free association with the United States.
- December 22, 1990
- The United Nations terminated the Trust Territory of the Pacific Islands for all but the Palau district.
- May 25, 1994
- The United Nations terminated the Trust Territory of the Pacific Islands for the Palau district, ending the territory, making Palau de facto independent, as it was not a territory of the United States.
- October 1, 1994
- Palau attained de jure independence, but it remained in free association with the United States. 
- December 11, 2012
- The Legislative Assembly of Puerto Rico enacted a concurrent resolution to request the President and the Congress of the United States to respond diligently and effectively, and to act on the demand of the people of Puerto Rico, as freely and democratically expressed in the plebiscite held on November 6, 2012, to end, once and for all, its current form of territorial status and to begin the process to admit Puerto Rico to the Union as a State. 
- Insular area
- Political divisions of the United States
- Political status of Puerto Rico
- Territories of the United States
- Unincorporated area
- Unorganized territory
- Unparished area
- U.S. Insular Areas Application of the U.S. Constitution, GAO Nov 1997 Report, p. 24. Viewed June 14, 2013.
- American Samoa remains technically unorganized since the U.S. Congress has not passed an Organic Act for the territory, but American Samoa is self-governing under a constitution that became effective on July 1, 1967.
- "Puerto Rico - territories of the United States". Puerto Rico Government. Government of the United States of America. Retrieved 8 December 2016.
- Definitions of insular area political organizations Archived September 25, 2012, at the Wayback Machine., "Unincorporated territory". Viewed June 14, 2013, and Government Accountability Office (GAO) Nov 1997 Report, U.S. Insular Areas Application of the U.S. Constitution, p. 35. Viewed June 14, 2013.
- See 8 U.S.C. § 1101(a)(36) and 8 U.S.C. § 1101(a)(38) Providing the term "State" and "United States" definitions on the U.S. Federal Code, Immigration and Nationality Act. 8 U.S.C. § 1101a
- Vignarajah, Krishanti. Political roots of judicial legitimacy: explaining the enduring validity of the ‘Insular Cases’., University of Chicago Law Review, 2010, p. 790. Viewed June 13, 2013.
- Consejo de Salud Playa de Ponce v. Johnny Rullan, Secretary of Health of the Commonwealth of Puerto Rico pp. 6–7. Viewed June 19, 2013.
- The Insular Cases: The Establishment of a Regime of Political Apartheid (2007) Juan R. Torruella (PDF), retrieved February 5, 2010
- Balzac v. People of Porto Rico, 258 U.S. 298 (1922)
- Rassmussen v. U S, 197 U.S. 516 (1905)
- "U.S. Census Bureau Releases 2010 Census Population Counts for Guam". 2010 Census. US Census. August 24, 2011. Archived from the original on September 24, 2011. Retrieved September 12, 2010.
- Midway Islands History. Janeresture.com. Retrieved on July 19, 2013.
- The World Almanac & Book of Facts 1901, p93
- "Transfer Day". Archived from the original on June 28, 2007. Retrieved August 10, 2006.
- "Municipalities of Puerto Rico". Statoids. Retrieved August 10, 2006.
- [ dead link] "Relationship with the Insular Areas". U.S. Department of the Interior. Archived from the original on May 26, 2006. Retrieved August 10, 2006.
- "Municipalities of Northern Mariana Islands". Statoids. Retrieved August 10, 2006.
- "Background Note: Palau". Bureau of East Asian and Pacific Affairs. Retrieved August 10, 2006.
- The Senate and the House of Representative of Puerto Rico Concurrent Resolution
- ^1 Scholars agreed as of 2009 in the Boston College Law Review, "Regardless of how Puerto Rico looked in 1901 when the Insular Cases were decided, or in 1922, today, Puerto Rico seems to be the paradigm of an incorporated territory as modern jurisprudence understands that legal term of art".  In November 2008 a district court judge ruled that a sequence of prior Congressional actions had the cumulative effect of changing Puerto Rico's status to incorporated.