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| | Reference.com/Encyclopedia/United States |
 | | The United States of America—also referred to as the United States, the USA, the U.S. America, the States, and (poetically) Columbia—is a democratic federal republic of fifty states located primarily in central North America. |
 | | However, the structure of the United States was profoundly changed in 1788 when the states replaced the Articles of Confederation with the United States Constitution; often, sources use the date each of the original 13 states adopted the Constitution as the date on that state "entered the Union" (became part of the United States). |
 | | The United States does not have an official language at federal level; nevertheless, English is spoken by the vast majority of the population and serves as the de facto language: English is the language used for legislation, regulations, executive orders, treaties, federal court rulings, and all other official pronouncements. |
| www.reference.com /browse/wiki/U.S. (5129 words) |
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