What constitutes the United States? What are the official definitions?
Geographically (and as a general reference), the United States of America includes all areas considered to be under the sovereignty of the United States, but does not include leased areas.
On May 14, 1959, the U.S. Board on Geographic Names issued the following definitions based partially on 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.
United States: The 50 States and the District of Columbia.
Continental United States: The 49 States (including Alaska, excluding Hawaii) located on the continent of North America, and the District of Columbia.
Conterminous United States: The 48 States and the District of Columbia; that is, the United States prior to January 3, 1959 (Alaska Statehood), wholly filling an unbroken block of territory and excluding Alaska and Hawaii. Although the official reference applies the term "conterminous," many use the word "contiguous," which is almost synonymous and better known.
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New Land Cover Maps Depict 15 Years of Change across America
Today, the U.S. Geological Survey (USGS) released the latest edition of the National Land Cover Database (NLCD) for the U.S. – the most comprehensive land cover database that the USGS has ever produced. The NLCD 2016 documents land cover change in the Lower 48 states from 2001 to 2016. During this 15-year period, 7.6 percent of the conterminous U.S. changed land cover at least once.
Mapping Public Lands in the United States
The Protected Areas Database of the United States (PAD-US) is the official inventory of public parks and other protected areas in all U.S. states and territories.
Volunteering to Map the Nation
As the USGS continues to celebrate “Mapping Month”, we again promote noteworthy contributors to The National Map Corps “crowdsourcing” project.
The National Map and National Atlas Merge
During this year, National Atlas of the United States and The National Map will transition into a combined single source for geospatial and cartographic information. This transformation is projected to streamline access to maps, data and information from the USGS National Geospatial Program (NGP).
Aquifers: Map of the Principal Aquifers of the United States
Aquifers: Map of the Principal Aquifers of the United States
Photograph of the United States at Night
The importance of electric power is demonstrated by this view from space of lights across the continental United States at night. Credit: NASA
A map of the United States depicting ecoregion borders
A map of the lower 48 states of the United States showing land cover overlayed with ecoregion boundaries.
1984-1986 - AVHRR Mosaic of United States
AVHRR data were collected by the second antenna at the Center and provided daily global coverage.
1974 Geologic Map of the United States.
King and Beikman's 1974 Geologic Map of the United States.