The contiguous United States or officially the conterminous United States, also known as the Lower 48, consists of the 48 adjoining U.S. states and the District of Columbia on the continent of North America. The terms exclude the non-contiguous states of Alaska and Hawaii and all other offshore insular areas, such as American Samoa, Guam, the Northern Mariana Islands, Puerto Rico, and the U.S. Virgin Islands. These differ from the related term continental United States, which includes Alaska (also on the North American continent but separated from the 48 states by British Columbia and Yukon of Canada) but excludes the Hawaiian Islands and all U.S. territories in the Caribbean and the Pacific.
The greatest distance (on a great-circle route) entirely within the 48 contiguous states is 2,802 miles (4,509 km) between Florida and the State of Washington; the greatest north–south line is 1,650 miles (2,660 km).
Together, the 48 contiguous states and the District of Columbia occupy an area of 3,119,884.69 square miles (8,080,464.3 km2). Of this area, 2,959,064.44 square miles (7,663,941.7 km2) is contiguous land, composing 83.65% of total U.S. land area, similar to the area of Australia. Officially, 160,820.25 square miles (416,522.5 km2) of the contiguous United States is water area, composing 62.66% of the nation's total water area.
The contiguous United States would be placed fifth on the list of countries and dependencies by area. The total area of the country, including Alaska and Hawaii, ranks third or fourth. In land area only, the country ranks fourth, ahead of Brazil, and Australia but behind Russia, Canada and China. Brazil is 431,000 square kilometers (166,000 sq mi) larger than the contiguous United States, but smaller than the entire United States, while Russia, Canada, and maybe China are the only countries larger than both. The 2020 census population of this area was 328,571,074, comprising 99.13% of the nation's population, and a density of 111.04 inhabitants/sq mi (42.872/km2), compared to 93.844/sq mi (36.233/km2) for the nation as a whole.
While conterminous U.S. has the precise meaning of contiguous U.S. (both adjectives meaning "sharing a common boundary"), other terms commonly used to describe the 48 contiguous states have a greater degree of ambiguity.
Continental and Mainland United States
Because Alaska is also a part of North America, the term continental United States also includes that state, so the term is qualified with the explicit inclusion of Alaska to resolve any ambiguity. On May 14, 1959, the United States Board on Geographic Names issued the following definitions based partially on the reference in the Alaska Omnibus Bill, which defined the continental United States as "the 49 States on the North American Continent and the District of Columbia..." The Board reaffirmed these definitions on May 13, 1999. However, even before Alaska became a state, it was properly included within the continental U.S. due to being an incorporated territory.
The term mainland United States is sometimes used synonymously with continental United States, but technically refers only to those parts of states connected to the landmass of North America, thereby excluding not only Hawaii and overseas insular areas, but also islands which are part of continental states but separated from the mainland, such as the Aleutian Islands (Alaska), San Juan Islands (Washington), the Channel Islands (California), the Keys (Florida), the barrier islands (Gulf and East Coast states), and Long Island (New York).
CONUS and OCONUS
CONUS, a technical term used by the U.S. Department of Defense, General Services Administration, NOAA/National Weather Service, and others, has been defined both as the continental United States, and as the 48 contiguous states. The District of Columbia is not always specifically mentioned as being part of CONUS.
The lower 48
The term lower 48 is also used to refer to the conterminous United States. The National Geographic style guide recommends the use of contiguous or conterminous United States instead of lower 48 when the 48 states are meant, unless used in the context of Alaska. Almost all of Hawaii is in fact south of the southernmost point of the conterminous United States, in Florida.
Zone of the Interior
During World War II, the first four numbered Air Forces of the United States Army Air Forces (USAAF) were said to be assigned to the Zone of the Interior by the American military organizations of the time—the future states of Alaska and Hawaii, then each only organized incorporated territories of the Union, were respectively covered by the Eleventh Air Force and Seventh Air Force during the war.
Terms used in the non-contiguous U.S. jurisdictions
Residents of Alaska, Hawaii and off-shore U.S. territories have unique labels for the contiguous United States because of their own locations relative to them.
Alaska became the 49th state of the United States on January 3, 1959. Alaska is on the northwest end of the North American continent, but separated from the rest of the United States West Coast by the Canadian province of British Columbia. The term Lower 48 has, for many years, been a common Alaskan equivalent for "contiguous United States"; today, many Alaskans use the term "Outside", though a few persons may use "Outside" to refer to any location not within Alaska.
Hawaii (consisting of nearly all the Hawaiian Islands) became the 50th state of the United States on August 21, 1959. It is the southernmost and so far, the latest state to join the Union. Not part of any continent, Hawaii is located in the Pacific Ocean, about 2,200 miles (3,541 km) from North America and almost halfway to Asia. In Hawaii and overseas American territories, for instance, the terms the Mainland or U.S. Mainland are often used to refer to the 49 states in North America.
Puerto Rico is an unincorporated territory of the United States located in the northeast Caribbean Sea, approximately 1,000 miles (1,609 km) southeast of Miami, Florida. Puerto Ricans born in Puerto Rico are U.S. citizens and are free to move to the mainland United States. The term Stateside Puerto Rican refers to residents of a U.S. state or the District of Columbia, who were born in or trace family ancestry to Puerto Rico.
U.S. Virgin Islands
The U.S. Virgin Islands is a U.S. territory located directly to the east of Puerto Rico in the Caribbean Sea. The term "stateside" is used to refer to the mainland, in relation to the U.S. Virgin Islands (see Stateside Virgin Islands Americans).
American Samoa is a U.S. territory located in the South Pacific Ocean in Polynesia, south of the equator — it is 2,200 miles (3,500 km) southwest of Hawaii. In American Samoa, the contiguous United States is called the "mainland United States" or "the states"; those not from American Samoa are called palagi (outsiders).
Non-contiguous areas within the contiguous United States
Apart from off-shore U.S. islands, a few continental portions of the contiguous U.S. are accessible by road only by traveling through Canada. Point Roberts, Washington; Elm Point, Minnesota; and the Northwest Angle in Minnesota are three such places. Alburgh, Vermont, is not directly connected by land, but is accessible by road via bridges from within Vermont and from New York. By contrast, Hyder, Alaska is physically part of contiguous Alaska and its easternmost town, but the only practical access is by road through Canada or by seaplane.
List of contiguous U.S. states
The 48 contiguous states are:
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Rhode Island
- South Carolina
- South Dakota
- West Virginia
In addition, the District of Columbia is within the contiguous United States.
- "What constitutes the United States, what are the official definitions?". www.usgs.gov.
- "United Airlines website". Archived from the original on April 2, 2012. Retrieved April 4, 2012.
Contiguous United States: The 48 adjoining states and the District of Columbia.
- Random House (1991). Random House Webster's College Dictionary. New York: Random House. ISBN 0-679-40110-5.
- These maps show the contiguous 48 states and D.C., but not Alaska and Hawaii.
- "Military Bases in the Contiguous United States". National Park Service, U.S. Department of the Interior. Retrieved November 28, 2012.
- "Soil Moisture Regimes of the Contiguous United States". U.S. Department of Agriculture. Retrieved November 28, 2012.
- Hyslop, Stephen G. (April 5, 1996). Political Geography of the United States. Guilford Press. p. 90.
- Pickover, Cliff. "The Longest Line in America!". University of Wisconsin.
- "HowStuffWorks "Geography of the United States - Geography"". Geography.howstuffworks.com. March 30, 2008. Retrieved October 29, 2013.
- "Field Listing: Area". The World Factbook. cia.gov.
- "Is China Bigger than the United States?". www.worldatlas.com. May 13, 2019.
- "Resident Population Data - 2010 Census". United States Census Bureau. Archived from the original on October 28, 2011. Retrieved January 30, 2011.
- "National Geographic Style Manual". Retrieved April 4, 2012.
The continental United States comprises the 48 contiguous, or coterminous, states plus Alaska.
- "United Cargo website". Archived from the original on April 2, 2012. Retrieved April 4, 2012.
Continental United States: The 48 adjoining states, Alaska and District of Columbia.
- "Alaska Airlines website". Retrieved April 4, 2012.
The Continental U.S. includes the lower 48 states as well as the State of Alaska, unless otherwise specified.
- "What constitutes the United States, what are the official definitions?". www.usgs.gov. Retrieved January 30, 2019.
- "In the absence of any such statement, Alaska would be regarded as a part of the continental United States." Inland Marine and Transportation Insurance (1949)
- Hyslop, Stephen G. (April 5, 1996). Political Geography of the United States. Guilford Press. p. 105-110.
- "Per Diem Rates (CONUS and OCONUS)". United States General Services Administration.
- "U.S. Navy Style Guide".
CONUS - "Continental United States." CONUS refers to the 48 contiguous states. It is not synonymous with United States. CONUS is acceptable on first reference."CONUS" seems to be used primarily by the American military and the Federal government and those doing business with them.
- "Glossary of Army Terms". Retrieved April 4, 2012.
"OCONUS: Outside Continental United States
- National Geographic Style Manual: conterminous, or contiguous, continental, continental United States at the Wayback Machine (archived 2 January 2016). "Use contiguous, or conterminous, for the 48 states. The continental United States comprises the 48 contiguous, or conterminous, states plus Alaska."
- National Geographic Style Manual: Alaska at the Wayback Machine (archived 28 October 2011). "The continental United States includes Alaska. In Alaska context, lower forty-eight or lower 48 may be used. Do not hyphenate lower 48 as an adjective. The term outside may be put in quotes on first reference if ambiguous. To distinguish the 48 states from the 49 or 50, use contiguous or conterminous."
- "Learn to Speak Alaskan - Alaskan Language Tips - Princess Lodges". princesslodges.com.
- "ALASKA: State Profile". Archived from the original on January 26, 2010. Retrieved December 6, 2013.
- Journal, Copper River Country. "Speaking Alaskan: Words Alaskans Say".
- Edles, Laura Desfor (2003). "'Race,' 'Ethnicity,' and 'Culture' in Hawai'i: The Myth of the 'Model Minority' State". In Loretta I. Winters and Herman L. DeBose (ed.) New Faces in a Changing America: Multiracial Identity in the 21st Century. SAGE Publications. p. 241. ISBN 9780761923008.
- Hyslop, Stephen G. (April 5, 1996). Political Geography of the United States. Guilford Press. p. 65.
- Five million Puerto Ricans now living in the mainland U.S. Archived 2013-12-18 at the Wayback Machine Caribbean Business. 27 June 2013. Vol 41. Issue 24. Retrieved 13 December 2013.
- "United States Virgin Islands". Encyclopaedia Britannica. Retrieved July 2, 2020.
- "U.S. Virgin Islands - Health and Safety". Frommers.com. Retrieved July 2, 2020.
- "American Samoa". Encyclopaedia Britannica. Retrieved July 2, 2020.
- Mack, Doug. The Not-Quite States Of America. pp. 67, 88, 91.
- Ross, Oakland (June 3, 2011). "Orphans of the atlas". Toronto Star. Retrieved June 5, 2011.