The United States of America is a federal constitutional republic comprising fifty states and a federal district. 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 the west across the Bering Strait, and the state of Hawaii is in the mid-Pacific. The United States also possesses several territories, or insular areas, scattered around the Caribbean and Pacific.
The nation was founded by thirteen colonies of Great Britain located along the Atlantic seaboard. Proclaiming themselves "states," they issued the Declaration of Independence on July 4, 1776. The rebellious states defeated Britain in the American Revolutionary War, the first successful colonial war of independence. A federal convention adopted the current United States Constitution on September 17, 1787; its ratification the following year made the states part of a single republic. The Bill of Rights, comprising ten constitutional amendments, was ratified in 1791.
In the nineteenth century, the United States acquired land from France, Spain, Great Britan, Mexico, and Russia, and annexed the Republic of Texas and the Republic of Hawaii. Disputes between the agrarian South and industrial North over states' rights and the expansion of the institution of slavery provoked the American Civil War of the 1860s. The North's victory prevented a permanent split of the country and led to the end of slavery in the United States. The Spanish-American War and World War I confirmed the nation's status as a military power. In 1945, the United States emerged from World War II as the first country with nuclear weapons, a permanent member of the United Nations Security Council, and a founding member of NATO. The United States entered the post–Cold War era as the only remaining superpower and a dominant economic, political, and cultural force in the world.
Although the United States has no official language at the federal level, English is the national language. English is the official language of at least twenty-eight states — some sources give a higher figure, based on differing definitions of "official." English and Hawaiian are both official languages in the state of Hawaii.
English is the de facto language of American government and the sole language spoken at home by 82% of Americans age five and older. Spanish is the second most commonly spoken language.
In 2003, about 215 million, or 82% of the population aged five years and older, spoke only English at home. Spanish, spoken by over 10% of the population at home, is the second most common language and the most widely taught foreign language. Immigrants seeking naturalization must know English. Some Americans advocate making English the country's official language, as it is in at least twenty-eight states. Both Hawaiian and English are official languages in Hawaii by state law. Several insular territories also grant official recognition to their native languages, along with English: Samoan and Chamorro are recognized by Samoa and Guam, respectively; Carolinian and Chamorro are recognized by the Northern Mariana Islands; Spanish is an official language of Puerto Rico. While neither has an official language, New Mexico has laws providing for the use of both English and Spanish, as Louisiana does for English and French. Other states, such as California, mandate the publication of Spanish versions of certain government documents.
The U.S. has fifty-eight national parks and hundreds of other federally managed parks, forests, and wilderness areas. Altogether, the U.S. government regulates 28.8% of the country's total land area. Most such public land comprises protected parks and forestland, though some federal land is leased for oil and gas drilling, mining, or cattle ranching.
Because of the United States' large size and wide range of geographic features, nearly every type of climate is represented. The climate is temperate in most areas, tropical in Hawaii and southern Florida, polar in Alaska, semi-arid in the Great Plains west of the 100th meridian, desert in the Southwest, Mediterranean in Coastal California, and arid in the Great Basin. Extreme weather is not uncommon — the states bordering the Gulf of Mexico are prone to hurricanes, and most of the world's tornadoes occur within the continental United States, primarily in the Midwest.
For information about tourism in the United States, please click on each State for detailed information.