United States

Lore & Background

Paleo-Indians migrated from North Asia to North America around 15,000 years ago and formed various civilizations. Beginning with the 1607 settlement of Virginia, British colonization established the Thirteen Colonies. The American Enlightenment, spread throughout the colonies in the 18th century, valued republicanism and liberalism. Clashes with the British Crown over taxation without representation, among other denied English rights, sparked the American Revolution, which led to the July 2, 1776, Lee Resolution formally declaring independence from Great Britain.

Two days later, the Declaration of Independence was adopted. Victory in the 1775–1783 Revolutionary War brought international recognition of U.S. sovereignty. The U.S. expanded westward through purchase, settlement and conquest of European- and Indigenous-controlled territory. As more states joined the Union, a sectional division over slavery led 11 Southern states to secede and form the Confederate States of America, fighting the Union in the Civil War of 1861–1865.

With the United States' victory and reunification, slavery was abolished. By 1900, the U.S. emerged as a great power, a status solidified after its involvement in World War I. Following Japan's attack on Pearl Harbor in 1941, it entered World War II on the Allied side. The war's aftermath left the U.S. and the Soviet Union as rival superpowers, vying for geopolitical dominance during the Cold War. The Soviet Union's collapse in 1991 left the U.S. as the world's sole superpower.

Reader's Guide

The U.S. federal government was established as a republic under the United States Constitution, with executive authority vested in a president. The Constitution created a separation of powers among legislative, executive, and judicial branches. The Congress is a bicameral national legislature composed of the House of Representatives (a lower house based on population) and the Senate (an upper house based on equal representation for each state). Federalism grants substantial autonomy to the 50 states.

A developed country, the United States ranks high in economic competitiveness, innovation, and higher education. Its economy accounts for over a quarter of nominal global GDP and has been the world's largest since about 1890. The U.S. is the wealthiest country, with the highest disposable household income per capita among OECD members, though its wealth inequality is highly pronounced. American culture, shaped by centuries of immigration, is diverse and globally influential.

The U.S. makes up nearly a third of global military spending and is widely considered to have the most powerful armed forces in the world. A member of numerous international organizations, it plays a dominant role in global political, cultural, economic, and military affairs.

Did You Know?

• Documented use of the phrase 'United States of America' dates back to January 2, 1776, in a letter by Stephen Moylan.
• The first known public usage of 'United States of America' was in an anonymous essay published in The Virginia Gazette on April 6, 1776.
• Thomas Jefferson wrote 'United States of America' in a rough draft of the Declaration of Independence on or after June 11, 1776.
• The term 'America' is the feminine form of the first name of Amerigo Vespucci, first used as a place name by German cartographers in 1507.

Historical Foundations and Early Publications

The first national atlas, titled the Statistical Atlas of the United States Based on the Results of the Ninth Census 1870, was published in 1874. Francis A. Walker, the Superintendent of the 1870 United States census, compiled it with contributions from many eminent men of science and several departments of the government. This edition contained population maps as well as economic and natural resources maps, including forests, precious metals, coal, climate, and crops. Henry Gannett, Chief Geographer of both the U.S. Census Bureau and the U.S. Geological Survey (USGS), led the production of three additional national atlases after 1874, with the last published in 1920.

The Comprehensive 1970 Edition

The next edition was issued in 1970, overseen by the USGS and its chief geographer Dr. Arch C. Gerlach. The atlas weighed twelve pounds, contained four hundred pages, and had a collection of 765 maps showing scientific information from various Federal sources regarding physical features, historical evolution, economic activities, sociocultural conditions, administrative subdivisions, and place in world affairs. It was primarily created for government officials and researchers to visualize country-wide patterns between environmental phenomena and human activities. 15,000 copies were printed at a price of US$100 (equivalent to $829 in 2025), making it cost-prohibitive for most Americans; a majority were bought by schools and libraries.

Digital Expansion and Public Domain Status

The final National Atlas was created in 1997 and published online through the first nine months of 2014. The USGS led its creation, with more than twenty U.S. federal agencies cooperating to produce it. This edition included the first online interactive mapping program offered by the Federal government, containing thousands of printable maps, fully documented digital cartographic datasets, wall maps, Web map and features services complying with Open Geospatial Consortium standards, multimedia dynamic maps, and innovative mapping applications. Its purpose was to provide a comprehensive view into geospatial data, increase geographic knowledge, and foster national self-awareness. Data from the atlas was also used with Canadian and Mexican information to produce continental-scale tools like the North American Environmental Atlas.

Program Termination and Data Archiving

In late 2013, mapping managers at the U.S. Geological Survey decided to end the program despite nationalatlas.gov receiving three times the use of nationalmap.gov. The demise was announced in February 2014, and the site went offline on October 1, 2014. Data is archived as the 1997-2014 Edition on the U.S. government's website and via The Internet Archive's Wayback Machine (printable maps can be downloaded but not previewed). The USGS continues to make a subset of data available under its National Map Small Scale Collection, with some datasets updated since retirement. Additional access is provided through EarthExplorer, the Mineral Resources Online Spatial Data site for small-scale geologic data, and the National Map Downloader or Staged Products.