Territories of the United States

Organized territories are lands under federal sovereignty (but not part of any state) which were given a measure of self-governance by Congress through an organic act subject to the Congress's plenary powers under the territorial clause of the Constitution's Article Four, section 3.[27]

The term unorganized was historically applied either to a newly acquired region not yet constituted as an organized incorporated territory (e.g. the Louisiana Purchase prior to the establishment of Orleans Territory and the District of Louisiana), or to a region previously part of an organized incorporated territory left "unorganized" after part of it had been organized and achieved the requirements for statehood (e.g. a large portion of Missouri Territory became unorganized territory for several years after its southeastern section became the state of Missouri).

Regions that have been admitted as states by the United States Constitution in addition to the original thirteen were (most often), prior to admission, territories or parts of territories of this kind. As the United States grew, the most populous parts of the organized territory would achieve statehood. Some territories existed only a short time before becoming states, while others remained territories for decades. The shortest-lived was Alabama Territory at two years, while New Mexico Territory and Hawaii Territory both lasted more than 50 years.

Of the current 50 states, 31 were at one time or another part of an organized, incorporated U.S. territory. In addition to the original 13, six subsequent states never were: Kentucky, Maine, and West Virginia were each set off from an already existing state;[28] Texas and Vermont were both sovereign states (only de facto sovereignty in Vermont's case, as the region was claimed by New York) at the time when they entered the Union; and California was set off from unorganized land ceded to the United States by Mexico in 1848 at the end of the Mexican–American War.

All of the five major U.S. territories are permanently inhabited and have locally elected territorial legislatures and executives and some degree of political autonomy. Four of the five are "organized", but American Samoa is technically "unorganized". All of the U.S. territories without permanent non-military populations are unorganized.

• American Samoa: territory since 1900; after the end of the Second Samoan Civil War, the Samoan Islands were divided into two regions. The U.S. took control of the eastern half of the islands.[63][30] In 1900, the Treaty of Cession of Tutuila took effect.[64] The Manuʻa islands became part of American Samoa in 1904, and Swains Island became part of American Samoa in 1925.[64] Congress ratified American Samoa's treaties in 1929.[64] For 51 years, the U.S. Navy controlled the territory.[41] American Samoa is locally self-governing under a constitution last revised in 1967.[30][note 15] The first elected governor of American Samoa was in 1977, and the first non-voting member of Congress was in 1981.[41] People born in American Samoa are U.S. nationals, but not U.S. citizens.[33][30] American Samoa is technically unorganized,[30] and its main island is Tutuila.[30]
• Guam: territory since 1899, acquired at the end of the Spanish–American War.[66] Guam is the home of Naval Base Guam and Andersen Air Force Base. It was organized under the Guam Organic Act of 1950, which granted U.S. citizenship to Guamanians and gave Guam a local government.[66] In 1968, the act was amended to permit the election of a governor.[66]
• Northern Mariana Islands: A commonwealth since 1986,[60][59] the Northern Mariana Islands together with Guam were part of the Spanish Empire until 1899 when the Northern Marianas were sold to the German Empire after the Spanish–American War.[67] Beginning in 1919, they were administered by Japan as a League of Nations mandate until the islands were captured by the United States in the Battle of Saipan and Battle of Tinian (June–August 1944) and the surrender of Aguigan (September 1945) during World War II.[67] They became part of the United Nations Trust Territory of the Pacific Islands (TTPI) in 1947, administered by the United States as U.N. trustee.[67][59] The other constituents of the TTPI were Palau, the Federated States of Micronesia and the Marshall Islands.[68] Following failed efforts in the 1950s and 1960s to reunify Guam and the Northern Marianas,[69] a covenant to establish the Northern Mariana Islands as a commonwealth in political union with the United States was negotiated by representatives of both political bodies; it was approved by Northern Mariana Islands voters in 1975, and came into force on March 24, 1976.[67][4] In accordance with the covenant, the Northern Mariana Islands constitution partially took effect on January 9, 1978, and became fully effective on November 4, 1986.[4] In 1986, the Northern Mariana Islands formally left U.N. trusteeship.[60] The abbreviations "CNMI" and "NMI" are both used in the commonwealth. Most residents in the Northern Mariana Islands live on Saipan, the main island.[4]
• Puerto Rico: unincorporated territory since 1899;[61] Puerto Rico was acquired at the end of the Spanish–American War,[70] and has been a U.S. commonwealth since 1952.[71] Since 1917, Puerto Ricans have been granted U.S. citizenship.[72] Puerto Rico was organized under the Puerto Rico Federal Relations Act of 1950 (Public Law 600). In November 2008, a U.S. District Court judge ruled that a series of Congressional actions have had the cumulative effect of changing Puerto Rico's status from unincorporated to incorporated.[73] The issue is proceeding through the courts, however,[74] and the U.S. government still refers to Puerto Rico as unincorporated. A Puerto Rican attorney has called the island "semi-sovereign".[75] Puerto Rico has a statehood movement, whose goal is to make the territory the 51st state.[49][76] See also Political status of Puerto Rico.
• U.S. Virgin Islands: purchased by the U.S. from Denmark in 1917 and organized under the Revised Organic Act of the Virgin Islands in 1954. U.S. citizenship was granted in 1927.[77] The main islands are Saint Thomas, Saint John and Saint Croix.[6]

Except for Guam, the inhabited territories lost population in 2020. Although the territories have higher poverty rates than the mainland U.S., they have high Human Development Indexes. Four of the five territories have another official language, in addition to English.[78][79]

The territories do not have administrative counties.[note 18] The U.S. Census Bureau counts Puerto Rico's 78 municipalities, the U.S. Virgin Islands' three main islands, all of Guam, the Northern Mariana Islands' four municipalities, and American Samoa's three districts and two atolls as county equivalents.[92][93] The Census Bureau also counts each of the U.S. Minor Outlying Islands as county equivalents.[92][93][94]

For statistical purposes, the U.S. Census Bureau has a defined area called the "Island Areas" which consists of American Samoa, Guam, the Northern Mariana Islands, and the U.S. Virgin Islands (every major territory except Puerto Rico).[1][95][96] The U.S. Census Bureau often treats Puerto Rico as its own entity or groups it with the states and D.C. (for example, Puerto Rico has a QuickFacts page just like the states and D.C.)[97] Puerto Rico data is collected annually in American Community Survey estimates (just like the states), but data for the other territories is collected only once every ten years.[98]

The American Samoa Fono

The five major inhabited territories contain the following governments and legislatures:

The following is the political party status of the governments of the U.S. territories following completion of the 2020 United States elections. Instances where local and national party affiliation differs, the national affiliation is listed second. Guam and the U.S. Virgin Islands have unicameral territorial legislatures.

Building where the Supreme Court of Guam is located

Each of the five major territories has its own local court system:

• High Court of American Samoa
• Supreme Court of Guam
• Supreme Court of the Northern Mariana Islands
• Supreme Court of Puerto Rico
• Supreme Court of the Virgin Islands

Of the five major territories, only Puerto Rico has an Article III federal district court (i.e., equivalent to the courts in the fifty states); it became an Article III court in 1966.[100] This means that, unlike other U.S. territories, federal judges in Puerto Rico have life tenure.[100] Federal courts in Guam, the Northern Mariana Islands and the U.S. Virgin Islands are Article IV territorial courts.[100][101] The following is a list of federal territorial courts, plus Puerto Rico's court:

• District Court of Guam (Ninth Circuit)
• District Court for the Northern Mariana Islands (Ninth Circuit)
• District Court for the District of Puerto Rico (not a territorial court) (First Circuit)
• District Court of the Virgin Islands (Third Circuit)

American Samoa does not have a federal territorial court, and so federal matters in American Samoa are sent to either the District court of Hawaii or the District court of the District of Columbia.[102] American Samoa is the only permanently inhabited region of the United States with no federal court.[102]

While the U.S. mainland is majority non-Hispanic White,[103] this is not the case for the U.S. territories. In 2010, American Samoa's population was 92.6% Pacific Islander (including 88.9% Samoan); Guam's population was 49.3% Pacific Islander (including 37.3% Chamorro) and 32.2% Asian (including 26.3% Filipino); the population of the Northern Mariana Islands was 34.9% Pacific Islander and 49.9% Asian; and the population of the U.S. Virgin Islands was 76.0% African American.[104] In 2019, Puerto Rico's population was 98.9% Hispanic or Latino, 67.4% white, and 0.8% non-Hispanic white.[7]

Throughout the 2010s, the U.S. territories (overall) lost population. The combined population of the five inhabited territories was 4,100,594 in 2010,[1] and 3,569,284 in 2020.[2][3][4][5][6][7]

The U.S. territories have high religiosity rates—American Samoa has the highest religiosity rate in the United States (99.3% religious and 98.3% Christian).[2]

The economies of the U.S. territories vary from Puerto Rico, which has a GDP of $104.989 billion in 2019, to American Samoa, which has a GDP of $636 million in 2018.[85] In 2018, Puerto Rico exported about $18 billion in goods, with the Netherlands as the largest destination.[105]

Guam's GDP shrank by 0.3% in 2018, the GDP of the Northern Mariana Islands shrank by 19.6% in 2018, Puerto Rico's GDP grew by 1.18% in 2019, and the U.S. Virgin Islands' GDP grew by 1.5% in 2018.[106][107][5][108][109] In 2017, American Samoa's GDP shrank by 5.8%, but then grew by 2.2% in 2018.[110]

American Samoa has the lowest per capita income in the United States—it has a per capita income comparable to that of Botswana.[111] In 2010, American Samoa's per capita income was $6,311.[112] As of 2010, the Manu'a District in American Samoa had a per capita income of $5,441, the lowest of any county or county-equivalent in the United States.[112] In 2018, Puerto Rico had a median household income of $20,166 (lower than the median household income of any state).[7][113] Also in 2018, Comerío Municipality, Puerto Rico had a median household income of $12,812 (the lowest median household income of any populated county or county-equivalent in the U.S.)[114] Guam has much higher incomes (Guam had a median household income of $48,274 in 2010.)[115]

The following two territories are claimed by multiple countries (including the United States),[14] and are not included in ISO 3166-2:UM. However, they are sometimes grouped with the U.S. Minor Outlying Islands. According to the GAO, "the United States conducts maritime law enforcement operations in and around Serranilla Bank and Bajo Nuevo [Bank] consistent with U.S. sovereignty claims."[14]

The U.S. Supreme Court, in its 1901–1905 Insular Cases opinions, ruled that the Constitution extended ex proprio vigore (i.e., of its own force) to the continental territories. The Court also established the doctrine of territorial incorporation, in which the Constitution applies fully to incorporated territories (such as the then-territories of Alaska and Hawaii) and partially in the unincorporated territories of Puerto Rico, Guam and, at the time, the Philippines (which is no longer a U.S. territory).[140][141][142]

In the 1901 Supreme Court case Downes v. Bidwell, the Court said that the U.S. Constitution did not fully apply in unincorporated territories because they were inhabited by "alien races".[143][144]

The U.S. had no unincorporated territories (also known as overseas possessions or insular areas) until 1856. Congress enacted the Guano Islands Act that year, authorizing the president to take possession of unclaimed islands to mine guano. The U.S. has taken control of (and claimed rights on) many islands and atolls, especially in the Caribbean Sea and the Pacific Ocean, under this law; most have been abandoned. It also has acquired territories since 1856 under other circumstances, such as under the Treaty of Paris (1898) which ended the Spanish–American War. The Supreme Court considered the constitutional position of these unincorporated territories in 1922 in Balzac v. People of Porto Rico, and said the following about a U.S. court in Puerto Rico:

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 ... It is created ... by 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.[145]^: 312

In Glidden Company v. Zdanok, the Court cited Balzac and said about courts in unincorporated territories: "Upon like considerations, Article III has been viewed as inapplicable to courts created in unincorporated territories outside the mainland ... and to the consular courts established by concessions from foreign countries".[146]^: 547 The judiciary determined that incorporation involves express declaration or an implication strong enough to exclude any other view, raising questions about Puerto Rico's status.[147]

In 1966, Congress made the United States District Court for the District of Puerto Rico an Article III district court. This (the only district court in a U.S. territory) sets Puerto Rico apart judicially from the other unincorporated territories, and U.S. district judge Gustavo Gelpi express the opinion that Puerto Rico is no longer unincorporated:

The court ... today holds that in the particular case of Puerto Rico, a monumental constitutional evolution based on continued and repeated congressional annexation has taken place. Given the same, the territory has evolved from an unincorporated to an incorporated one. Congress today, thus, must afford Puerto Rico and the 4,000,000 United States citizens residing therein all constitutional guarantees. To hold otherwise, would amount to the court blindfolding itself to continue permitting Congress per secula seculorum to switch on and off the Constitution.[148]

In Balzac, the Court defined "implied":[145]^: 306

Had Congress intended to take the important step of changing the treaty status of Puerto Rico by incorporating it into the Union, it is reasonable to suppose that it would have done so by the plain declaration, and would not have left it to mere inference. Before the question became acute at the close of the Spanish War, the distinction between acquisition and incorporation was not regarded as important, or at least it was not fully understood and had not aroused great controversy. Before that, the purpose of Congress might well be a matter of mere inference from various legislative acts; but in these latter days, incorporation is not to be assumed without express declaration, or an implication so strong as to exclude any other view.

On June 5, 2015, the U.S. Court of Appeals for the District of Columbia ruled 3–0 in Tuaua v. United States to deny birthright citizenship to American Samoans, ruling that the guarantee of such citizenship to citizens in the Fourteenth Amendment does not apply to unincorporated U.S. territories. In 2016 the U.S. Supreme Court declined to review the appellate court's decision.[149]

In 2018, the United States Court of Appeals for the 7th Circuit upheld the District Court decision in Segovia v. United States, which ruled that former Illinois residents living in Puerto Rico, Guam, and the U.S. Virgin Islands did not qualify to cast overseas ballots according to their last registered address on the U.S. mainland.[150] (Residents of the Northern Marianas and American Samoa, however, were still allowed to cast such ballots.) In October 2018, the U.S. Supreme Court declined to review the 7th Circuit's decision.

On June 15, 2021, the United States Court of Appeals for the Tenth Circuit ruled 2–1 in Fitisemanu v. United States to deny birthright citizenship to American Samoans and not to overrule the Insular Cases. The court cited Downes and ruled that "neither constitutional text nor Supreme Court precedent" demands that American Samoans should be given automatic birthright citizenship.[151] The case is now pending certiorari before the U.S. Supreme Court.[152] On April 21, 2022, in the case United States v. Vaello Madero, Justice Gorsuch urged the Supreme Court to overrule the Insular Cases when possible as it "rests on rotten foundation" and called the cases "shameful".[153][154][155]

In analyzing the Insular Cases, Christina Duffy Ponsa of the New York Times said the following: "To be an unincorporated territory is to be caught in limbo: although unquestionably subject to American sovereignty, they are not considered part of the United States for certain purposes but not others. Whether they are part of the United States for purposes of the Citizenship Clause remains unresolved."[11]

The 2016 Supreme Court case Puerto Rico v. Sanchez Valle ruled that territories do not have their own sovereignty.[9] That year, the Supreme Court declined to rule on a lower-court ruling in Tuaua v. United States that American Samoans are not U.S. citizens at birth.[36][37]

The Supreme Court ruled in 2022 in United States v. Vaello-Madero that Congress is not required to extend all benefits to Puerto Ricans, and that the exclusion of Puerto Ricans from the Supplemental Security Income program was permitted under the constitution.[156]

In Rassmussen v. U.S., the Supreme Court quoted from Article III of the 1867 treaty for the purchase of Alaska:

"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 ... 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.[157]^: 522

The act of incorporation affects the people of the territory more than the territory itself by extending the Privileges and Immunities Clause of the Constitution to them, such as its extension to Puerto Rico in 1947; however, Puerto Rico remains unincorporated.[147]

Rassmussen arose from a criminal conviction by a six-person jury in Alaska under federal law. The court held that Alaska had been incorporated into the U.S. in the treaty of cession with Russia,[158] and the congressional implication was strong enough to exclude any other view:[157]^: 523

That Congress, shortly following the adoption of the treaty with Russia, clearly contemplated the incorporation of Alaska into the United States as a part thereof, we think plainly results from the act of July 20, 1868, concerning internal revenue taxation ... and the act of July 27, 1868 ... extending the laws of the United States relating to customs, commerce, and navigation over Alaska, and establishing a collection district therein ... And this is fortified by subsequent action of Congress, which it is unnecessary to refer to.

Concurring justice Henry Brown agreed:[157]^: 533–34

Apparently, acceptance of the territory is insufficient in the opinion of the court in this case, since the result that Alaska is incorporated into the United States is reached, not through the treaty with Russia, or through the establishment of a civil government there, but from the act ... extending the laws of the United States relating to the customs, commerce, and navigation over Alaska, and establishing a collection district there. Certain other acts are cited, notably the judiciary act ... making it the duty of this court to assign ... the several territories of the United States to particular Circuits.

In Dorr v. U.S., the court quoted Chief Justice John Marshall from an earlier case:[159]^: 141–2

The 6th article of the treaty of cession contains the following provision: "The inhabitants of the territories which His Catholic Majesty cedes the United States by this treaty shall be incorporated in the Union of the United States as soon as may be consistent with the principles of the Federal Constitution and admitted to the enjoyment of the privileges, rights, and immunities of the citizens of the United States ..." This treaty is the law of the land and admits the inhabitants of Florida to the enjoyment of the privileges, rights, and immunities of the citizens of the United States. It is unnecessary to inquire whether this is not their condition, independent of stipulation. They do not, however, participate in political power; they do not share in the government till Florida shall become a state. In the meantime Florida continues to be a territory of the United States, governed by virtue of that clause in the Constitution which empowers Congress "to make all needful rules and regulations respecting the territory or other property belonging to the United States".

In Downes v. Bidwell, the court said: "The same construction was adhered to in the treaty with Spain for the purchase of Florida ... the 6th article of which provided that the inhabitants should 'be incorporated into the Union of the United States, as soon as may be consistent with the principles of the Federal Constitution'."[160]^: 256

Justice Brown first mentioned incorporation in Downes:[160]^: 321–22

In view of this it cannot, it seems to me, be doubted that the United States continued to be composed of states and territories, all forming an integral part thereof and incorporated therein, as was the case prior to the adoption of the Constitution. Subsequently, the territory now embraced in the state of Tennessee was ceded to the United States by the state of North Carolina. To ensure the rights of the native inhabitants, it was expressly stipulated that the inhabitants of the ceded territory should enjoy all the rights, privileges, benefits, and advantages set forth in the ordinance of the late Congress for the government of the western territory of the United States.

In Downes, the court said:

Owing to a new war between England and France being upon the point of breaking out, there was need for haste in the negotiations, and Mr. Livingston took the responsibility of disobeying his (Mr. Jefferson's) instructions, and, probably owing to the insistence of Bonaparte, consented to the 3d article of the treaty (with France to acquire the territory of Louisiana), which provided that "the inhabitants of the ceded territory shall be incorporated in the Union of the United States, and admitted as soon as possible, according to the principles of the Federal Constitution, to the enjoyment of all the rights, advantages, and immunities of citizens of the United States; and in the meantime they shall be maintained and protected in the free enjoyment of their liberty, property, and the religion which they profess." [8 Stat. at L. 202.] This evidently committed the government to the ultimate, but not to the immediate, admission of Louisiana as a state ...[160]^: 252

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".[161] 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.[162] The United States Supreme Court, in 2021, held that the territorial clause of the constitution allowed wide congressional latitude in mandating "reasonable" tax and benefit schemes in Puerto Rico and the other territories that are different from the states, but did not address the incorporated/unincorporated distinction. In a concurrence, one of the justices opined that it was time to overrule the Insular Cases and the incorporation doctrine, as wrongly decided.[138]

At various times during the 19th century, large parts of the Great Plains were unorganized territory. After the Louisiana Purchase from France in 1803, the entire region was part of the Louisiana Territory until 1812 and the Missouri Territory until 1821. In 1821 the Missouri Compromise created the State of Missouri from the territory, and the rest of the region was left unorganized. The Kansas–Nebraska Act of 1854 created the Kansas and Nebraska Territories, bringing organized government to the region once again. The creation of Kansas and Nebraska left the Indian Territory as the only unorganized territory in the Great Plains.

In 1858, the western part of the Minnesota Territory became unorganized when it was not included in the new state of Minnesota; this area was organized in 1861 as part of the Dakota Territory. On May 2, 1890, the western half of the Indian Territory was organized as Oklahoma. The remainder was incorporated into the State of Oklahoma upon its admission to the union in 1907.

Alaska was an unorganized territory between its acquisition from Russia in 1867 and the creation of Alaska Territory in 1912. Hawaii was as well from the time of its annexation by the U.S. in 1898 until organized as Hawaii Territory in 1900.

(All areas that have become U.S. states outside of the Thirteen Colonies)

• Corn Islands (1914–1971): leased for 99 years under the Bryan–Chamorro Treaty, but returned to Nicaragua after the treaty was annulled in 1970
• Line Islands: disputed claim with the United Kingdom. U.S. claim to most of the islands was ceded to Kiribati upon its independence in 1979, but the U.S. retained Kingman Reef, Palmyra Atoll and Jarvis Island
• Panama Canal Zone (1903–1979): sovereignty returned to Panama under the Torrijos–Carter Treaties of 1978. The U.S. retained a military base and control of the canal until December 31, 1999.
• Commonwealth of the Philippines: Philippines (1898–1946): military government, 1898–1902; insular government, 1901–1935; commonwealth government, 1935–1942 and 1945–1946 (islands under Japanese occupation, 1942–1945 and puppet state, 1943–1945); granted independence on July 4, 1946[163]
• Phoenix Islands: disputed claim with the United Kingdom; U.S. claim ceded to Kiribati upon its independence in 1979 (Baker and Howland Islands, sometimes considered part of this group, are retained by the U.S.)
• Quita Sueño Bank (1869–1981): claimed under the Guano Islands Act; claim abandoned in a treaty ratified September 7, 1981
• Roncador Bank (1856–1981): claimed under the Guano Islands Act; ceded to Colombia in treaty ratified September 7, 1981
• Serrana Bank: claimed under the Guano Islands Act; ceded to Colombia in treaty ratified September 7, 1981[164]
• Swan Islands (1863–1972): claimed under the Guano Islands Act; ceded to Honduras in a 1972 treaty

• Cuba (1899–1902, 1906–1909, and 1917–1922)
• Dominican Republic (1916–1924 and 1965–66)
• Haiti (1915–1934, 1994–1995)
• Nanpō Islands and Marcus Island (1945–1968): Occupied after World War II, and returned to Japan by mutual agreement
• Nicaragua (1912–1933)
• Panama, 1989–1990
• Ryukyu Islands, including Okinawa (1952–1972): returned to Japan in an agreement including the Daitō Islands[165]
• Trust Territory of the Pacific Islands (1947–1986): U.N. trust territory administered by the U.S.; included the Marshall Islands, the Federated States of Micronesia, and Palau, which are sovereign states (that have entered into a Compact of Free Association with the U.S.), along with the Commonwealth of the Northern Mariana Islands.
• Veracruz (1914): after the Tampico Affair during the Mexican Revolution
• American Shanghai (1848-1863): A former enclave in modern day Shanghai China.

• Participation in the Occupation of the Rhineland (1918–1921)
• Participation in the Occupation of Constantinople (1918–1923)
• Participation in the Occupation of Austria-Hungary (1918–1919)
• Occupation of Greenland in World War II (1941–1945)[166]
• Occupation of Iceland in World War II (1941–1946);[166] military base retained until 2006.
• Allied Military Government for Occupied Territories, in Allied-controlled sections of Italy from the July 1943 invasion of Sicily until the September armistice with Italy. AMGOT continued in newly liberated areas of Italy until the end of the war, and also existed in France.
• Clipperton Island (1944–1945): occupied territory, returned to France on October 23, 1945.
• United States Army Military Government in Korea: Occupation south of the 38th parallel from 1945 to 1948.
• American zones of Allied-occupied Germany (1945–1949)
• Occupation of Japan (1945–1952) after World War II
• American occupation zones in Allied-occupied Austria and Vienna (1945–1955)
• American occupation zone in West Berlin (1945–1990)
• Free Territory of Trieste (1947–1954): The U.S. co-administered a portion of the territory (between the Kingdom of Italy and the former Kingdom of Yugoslavia) with the United Kingdom.
• Grenada invasion and occupation (1983)
• Coalition Provisional Authority (Iraq, 2003–2004)
• Green Zone, Iraq (March 20, 2003 – December 31, 2008)[167]

View of El Yunque National Forest in Puerto Rico

The USDA says the following about the U.S. territories (plus Hawaii):

[The U.S. territories, plus Hawaii] include virtually all the Nation's tropical forests as well as other forest types including subtropical, coastal, subalpine, dry limestone, and coastal mangrove forests. Although distant from America's geographic center and from each other—and with distinctive flora and fauna, land use history, and individual forest issues—these rich and diverse ecosystems share a common bond of change and challenge.[168]

Forests in the U.S. territories are vulnerable to invasive species and new housing developments.[168] El Yunque National Forest in Puerto Rico is the only tropical rain forest in the United States National Forest system.[169]

American Samoa has 80.84% forest cover and the Northern Mariana Islands has 80.37% forest cover—these are among the highest forest cover percentages in the United States (only Maine and New Hampshire are higher).[170][note 19]

Left: Many-colored fruit dove (found in American Samoa); Right: Golden white-eye (found only in the Northern Mariana Islands)

U.S. territories have many bird species that are endemic (not found in any other location).[168]

Introduction of the invasive brown tree snake has harmed Guam's native bird population—nine of twelve endemic species have become extinct, and the territorial bird (the Guam rail) is extinct in the wild.[168]

Puerto Rico has several endemic bird species, such as the critically endangered Puerto Rican parrot, the Puerto Rican flycatcher, and the Puerto Rican spindalis.[171] The Northern Mariana Islands has the Mariana swiftlet, Mariana crow, Tinian monarch and golden white-eye (all endemic).[172] Birds found in American Samoa include the many-colored fruit dove,[173] the blue-crowned lorikeet, and the Samoan starling.[174]

The Wake Island rail (now extinct) was endemic to Wake Island,[175] and the Laysan duck is endemic to Midway Atoll and the Northwest Hawaiian Islands.[176] Palmyra Atoll has the second-largest red-footed booby colony in the world,[177] and Midway Atoll has the largest breeding colony of Laysan albatross in the world.[178][179]

The American Birding Association currently excludes the U.S. territories from their "ABA Area" checklist.[180]

American Samoa has several reptile species, such as the Pacific boa (on the island of Ta‘ū) and Pacific slender-toed gecko.[181] American Samoa has only a few mammal species, such as the Pacific (Polynesian) sheath-tailed bat, as well as oceanic mammals such as the Humpback whale.[182][183] Guam and the Northern Mariana Islands also have a small number of mammals, such as the Mariana fruit bat;[184] oceanic mammals include Fraser's dolphin and the Sperm whale. The fauna of Puerto Rico includes the common coquí (frog),[185] while the fauna of the U.S. Virgin Islands includes species found in Virgin Islands National Park (including 302 species of fish).[186]

American Samoa has a location called Turtle and Shark which is important in Samoan culture and mythology.[187]

There are two National Parks in the U.S. territories: the National Park of American Samoa, and Virgin Islands National Park.[188][189] The National Park Service also manages War in the Pacific National Historical Park on Guam.[190] There are also National Natural Landmarks, National Wildlife Refuges (such as Guam National Wildlife Refuge), El Yunque National Forest in Puerto Rico, and the Pacific Remote Islands Marine National Monument (which includes the U.S. Minor Outlying Islands).

• 
  Amata Coleman Radewagen (R), (American Samoa)
• 
  Michael San Nicolas (D), (Guam)
• 
  Gregorio Sablan (D), (Northern Mariana Islands)
• 
  Jenniffer González (R), (Puerto Rico)
• 
  Stacey Plaskett (D), (U.S. Virgin Islands)

• 
  Lemanu Peleti Mauga (NP-D), (American Samoa)
• 
  Lou Leon Guerrero (D), (Guam)
• 
  Ralph Torres (R), (Northern Mariana Islands)
• 
  Pedro Pierluisi (PNP-D), (Puerto Rico)
• 
  Albert Bryan (D), (U.S. Virgin Islands)

• 
  Tutuila and Aunu'u (American Samoa)
• 
  Guam
• 
  Saipan (Northern Mariana Islands)
• 
  Puerto Rico
• 
  U.S. Virgin Islands

• 
  Baker Island
• 
  Howland Island
• 
  Jarvis Island
• 
  Johnston Atoll
• 
  Kingman Reef
• 
  Midway Atoll
• 
  Navassa Island
• 
  Palmyra Atoll
• 
  Wake Island

• 
  American Samoa
• 
  Guam
• 
  Northern Mariana Islands
• 
  Puerto Rico
• 
  U.S. Virgin Islands
• 
  U.S. exclusive economic zone

• Colony of Liberia, established by Americans but never under administration of the United States
• Enabling act (United States)
• Historic regions of the United States
• Insular area
• List of extreme points of the United States
• List of states and territories of the United States
• Organic act
• Organized incorporated territories of the United States
• Territorial evolution of the United States
• U.S. territorial sovereignty