Territories of the United States in the context of "United States Virgin Islands"

An island country, island state, or island nation is a country whose primary territory consists of one or more islands or parts of islands. Approximately 25% of all independent countries are island countries. Island countries are historically more stable than many continental states but are vulnerable to conquest by naval superpowers. Indonesia is the largest and most populated island country in the world (and the fourth most populated country overall).

There are great variations between island country economies: they may rely mainly on extractive industries, such as mining, fishing and agriculture, and/or on services such as transit hubs, tourism, and financial services. Many islands have low-lying geographies and their economies and population centers develop along coast plains and ports; such states may be vulnerable to the effects of climate change, especially sea level rise.

The barrios of Puerto Rico are the third-level administrative divisions defined with geographic boundaries serving as the primary legal subdivisions of the 78 municipalities in the archipelago and island of Puerto Rico, an unincorporated territory of the U.S. Amounting to 902 wards or boroughs equivalent to minor civil divisions in the U.S., like cities, townships, and parishes, barrios are under the governmental authority of the popularly elected strong mayor and unicameral legislature governing the municipality within which they are located. Barrios are subdivided into numerous subbarrios, districts, communities, and/or sectors.

Except for San Juan, Ponce, Florida, and Vieques, all municipalities have a barrio equivalent to a downtown area in the U.S. called pueblo, officially known as barrio-pueblo (literally "neighborhood-town"), which typically is the site of the historic Spanish colonial settlement, administrative center, and urban core of the municipality. Of the 902 barrios proper, 828 are barrios and 74 barrios-pueblos.

Puerto Rico (abbreviated PR), officially the Commonwealth of Puerto Rico, is a self-governing Caribbean archipelago and island organized as an unincorporated territory of the United States under the designation of commonwealth. Located about 1,000 miles (1,600 km) southeast of Miami, Florida, between the Dominican Republic in the Greater Antilles and the U.S. Virgin Islands in the Lesser Antilles, it consists of the eponymous main island and numerous smaller islands, including Vieques, Culebra, and Mona. With approximately 3.2 million residents, it is divided into 78 municipalities, of which the most populous is the capital municipality of San Juan, followed by those within the San Juan metropolitan area. Spanish and English are the official languages of the government, though Spanish predominates.

Puerto Rico was settled by a succession of Amerindian peoples beginning 2,000 to 4,000 years ago; these included the Ortoiroid, Saladoid, and Taíno. It was claimed by Spain following the arrival of Christopher Columbus in 1493 and subsequently colonized by Juan Ponce de León in 1508. Puerto Rico was contested by other European powers into the 18th century but remained a Spanish possession for the next 400 years. The decline of the Indigenous population, followed by an influx of Spanish settlers, primarily from the Canary Islands and Andalusia, and African slaves vastly changed the cultural and demographic landscape of the archipelago. Within the Spanish Empire, Puerto Rico played a secondary but strategically significant role compared to larger and wealthier colonies like Peru and New Spain. By the late 19th century, a distinct Puerto Rican identity began to emerge, centered on a fusion of European, African, and Indigenous elements. In 1898, following the Spanish–American War, Puerto Rico was acquired by the United States.

The United States of America (USA), also known as the United States (U.S.) or America, is a country primarily located in North America. It is a federal republic of 50 states and a federal capital district, Washington, D.C. The 48 contiguous states border Canada to the north and Mexico to the south, with the semi-exclave of Alaska in the northwest and the archipelago of Hawaii in the Pacific Ocean. The United States also asserts sovereignty over five major island territories and various uninhabited islands in Oceania and the Caribbean. It is a megadiverse country, with the world's third-largest land area and third-largest population, exceeding 340 million.

Paleo-Indians first migrated from North Asia to North America over 12,000 years ago, and formed various civilizations. Spanish colonization established Spanish Florida in 1513, the first European colony in what is now the continental United States. British colonization followed with the 1607 settlement of Virginia, the first of the Thirteen Colonies. Enslavement of Africans was practiced in all colonies by 1770 and supplied most of the labor for the Southern Colonies' plantation economy. Clashes with the British Crown over taxation and lack of parliamentary representation sparked the American Revolution, leading to the Declaration of Independence on July 4, 1776. Victory in the 1775–1783 Revolutionary War brought international recognition of U.S. sovereignty and fueled westward expansion, dispossessing native inhabitants. As more states were admitted, a North–South division over slavery led the Confederate States of America to attempt secession and fight the Union in the 1861–1865 American Civil War. With the United States' victory and reunification, slavery was abolished nationally. By 1900, the country had established itself as a great power, a status solidified after its involvement in World War I. Following Japan's attack on Pearl Harbor in 1941, the U.S. entered World War II. Its aftermath left the U.S. and the Soviet Union as rival superpowers, competing for ideological dominance and international influence during the Cold War. The Soviet Union's collapse in 1991 ended the Cold War, leaving the U.S. as the world's sole superpower.

An economic and monetary union (EMU) is a type of trade bloc that features a combination of a common market, customs union, and monetary union. Established via a trade pact, an EMU constitutes the sixth of seven stages in the process of economic integration. An EMU agreement usually combines a customs union with a common market. A typical EMU establishes free trade and a common external tariff throughout its jurisdiction. It is also designed to protect freedom in the movement of goods, services, and people. This arrangement is distinct from a monetary union (e.g., the Latin Monetary Union), which does not usually involve a common market. As with the economic and monetary union established among the 27 member states of the European Union (EU), an EMU may affect different parts of its jurisdiction in different ways. Some areas are subject to separate customs regulations from other areas subject to the EMU. These various arrangements may be established in a formal agreement, or they may exist on a de facto basis. For example, not all EU member states use the Euro established by its currency union, and not all EU member states are part of the Schengen Area. Some EU members participate in both unions, and some in neither.

Territories of the United States, Australian External Territories and New Zealand territories each share a currency and, for the most part, the market of their respective mainland states. However, they are generally not part of the same customs territories.

An island is a landmass (smaller than a continent) that is surrounded by water. Many island countries are spread over an archipelago, as is the case with Indonesia, Japan, and the Philippines—these countries consist of thousands of islands. Others consist of a single island, such as Barbados, Dominica, and Nauru; a main island and some smaller islands, such as Cuba, Iceland, and Sri Lanka; a part of an island, such as Brunei, the Dominican Republic, East Timor, and the Republic of Ireland; or one main island but also sharing borders in other islands, such as the United Kingdom (Great Britain and a part of Ireland).

The list also includes two states in free association with New Zealand, the Cook Islands and Niue, as well as two states with limited diplomatic recognition which have de facto control over territories entirely on the islands, Northern Cyprus and Taiwan. In total, 50 island countries have been included in the lists.

In the United States, a county or county equivalent is an administrative subdivision of a state or territory, typically with defined geographic boundaries and some level of governmental authority. The term "county" is used in 48 states, while Louisiana and Alaska have functionally equivalent subdivisions called parishes and boroughs, respectively. Counties and other local governments exist as a matter of U.S. state law, so the specific governmental powers of counties may vary widely between the states, with many providing some level of services to civil townships, municipalities, and unincorporated areas. Certain municipalities are in multiple counties. Some municipalities have been consolidated with their county government to form consolidated city-counties or have been legally separated from counties altogether to form independent cities. Conversely, counties in Connecticut and Rhode Island, eight of Massachusetts's 14 counties, and Alaska's Unorganized Borough have no government power, existing only as geographic distinctions.

The United States Census Bureau uses the term "county equivalent" to describe places that are comparable to counties, but called by different names. Louisiana parishes, the organized boroughs of Alaska, independent cities, and the District of Columbia are equivalent to counties for administrative purposes. Alaska's Unorganized Borough is further divided into 11 census areas that are statistically equivalent to counties. In 2024, the U.S. Census Bureau began to also recognize Connecticut's councils of governments, which took over some of the regional powers from the state's former county governments, as county equivalents.