The United States of America (also called the United States, the U.S., the USA, America, and the States) is a federal constitutional republic comprising fifty states and a federal district.

The United States is the fourth largest country by total area, and the third largest by both land area and population. It is one of the world’s most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The United States has the world’s largest national economy, which is fueled by abundant natural resources, a well-developed infrastructure, and high productivity. The United States has been a leader in scientific research and technological innovation since the late 19th century.

Population312 million
Area9,826,675 km2 / 3,794,101 sq mi
GDP$15 trillion (2011)
Capital CityWashington, DC
Largest CityNew York City
CurrencyU.S. Dollar

The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to its east and Russia to its west, across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific. The country also possesses several territories in the Pacific and Caribbean.

The nation retains United States customary units, comprising mainly former British imperial units such as miles, yards, and degrees Fahrenheit. Distinct units include the U.S. gallon and U.S. pint volume measurements. The United States is one of only three countries that do not rely primarily on the International System of Units. However, metric units are increasingly used in science, medicine, and many industrial fields.


On 17-22 September 2012, the United States will play host to the world’s standardization community as the American National Standards Institute (ANSI) welcomes ISO to San Diego, California. The official venue is the San Diego Marriott Marquis Hotel & Marina– a full- service hotel and meeting center located in downtown San Diego, just two miles from the San Diego International Airport.


Participation in the ISO GA 2012 is open to delegates appointed by ISO members and representatives of invited international organizations. For more information, contact your national standards body.

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