USA map and geographical facts - World atlas

including the Blue Ridge Mountains in Virginia and the Great Smoky Mountains along the North Carolina-Tennessee border. For a long time these ranges constituted a barrier to inland settlement. In New York State the valley of the Mohawk River divides the mountains of the Appalachians from the Adirondacks, which are a southern extension of the ancient granite mass of the Canadian Shield. Traveling up this valley, from east to west, the early settlers were able to find a way through the range that led on to the land bordering the Great Lakes and the Ohio country beyond.

The original vegetation on these mountains was broadleaf deciduous forest of oak, ash, beech, and maple grading into yellow birch, hemlock, and pine towards the north. During the eighteenth and nineteenth centuries much of this forest area was cleared for farming, but declining agriculture in New England and the abandonment of farmland has brought widespread regeneration of tree growth. Flying across eastern America, much of the landscape still gives the impression of continuous woodland.

The coastal plain to the southeast through the Carolinas and Georgia is generally low-lying, and includes many areas of swamp. Nearly 1,700 km (more than 1,000 miles) of barrier islands and sandbars run parallel to the shore and are popular seaside resort areas for the inland population, despite being exposed to occasional hurricanes.

To the west of the Appalachian Range lies the enormous continental drainage basin of the Mississippi-Missouri river system. This basin is about 2,500 km (1,500 miles) wide, extending south from the Canadian border to the Gulf of Mexico. At its northern limit there are the hills along Lake Superior, a vestige of the Canadian Shield. What are called the Central Lowlands of this drainage basin are bounded on the east by the low plateaus of Kentucky and Tennessee. To the west of the Mississippi lie vast areas planted in wheat, and eventually grasslands, as the Great Plains reach 1,500 km (900 miles) across to the foothills of the Rocky Mountains.

Once the home of such tribes as the Mandan, the Omaha, and the Kansa Indians (settled farmers near the Missouri River), and the nomadic Blackfoot, Crow, and Arapaho further west, most of the plains had been taken by incoming ranchers and farmers by the end of the nineteenth century. Former range land was planted in wheat and maize. These crops were hugely productive at first, but overcropping and dry years led to severe soil deterioration in the first decades of the twentieth century. This reached a climax in the disasters of the 1930s, when a large part of the region became a "dustbowl." Although diversification of grain crops, contour plowing, and widespread irrigation have helped to restore agricultural productivity, some areas are still highly sensitive to climatic variation, especially where the original terrain was semidesert. Combined with fluctuations in grain prices, agriculture remains a risky business in a region where much of the land is marginal.

The mountain ranges of the western Cordillera, as it extends south from Canada, are divided by a number of high plateaus and deep valleys. There are two main systems, to the west and the east. The northern and central Rocky Mountains are the eastern arm facing out across the Great Plains, with the Grand Tetons forming spectacular ridges in Wyoming. The southern Rockies of Colorado and New Mexico—the remains of an ancient granite plateau—are also weathered into a series of striking peaks. In Colorado there are more than 1,000 mountains of 3,000 m (10,000 ft) or more. As with the mountains on the east of the continent, the Rockies were a major obstacle for westward-heading settlers. One major route lay through the Wyoming Basin, a rangeland where bison once grazed, and where yesterday's pioneer trails have become interstate highways.

On the lower slopes of the Rockies grow a mixture of pinon pines and juniper scrub, with ponderosa pine, spruce, and fir at higher altitudes. Wildlife includes elk, deer, moose, mountain sheep, bear, and a variety of smaller animals. National parks such as Yellowstone

and Grand Teton provide an opportunity to see these animals in dramatic natural settings, and draw millions of visitors to the region every year.

High plateaus, rocky ranges, and desert basins extend westward across the states of Utah, Arizona, and Nevada, seamed in many places by vast, abrupt canyons, of which the Grand Canyon of the Colorado River is the most spectacular. On the Pacific side of these plateaus is the western branch of the cordillera. This forms a chain of mountains consisting of the Sierra Nevada in the south and the Cascade Range to the north. Stretching from Washington through Oregon to Lassen Peak in California (3,187 m; 10,456 ft), the Cascades include several large volcanoes, including Mt Saint Helens which erupted violently in 1980. The Sierra Nevada faces out over the fertile Central Valley of California, with its fruit and vegetable growing, viticulture, cotton, other crops, and livestock. In the early days long dry summers made farming difficult in the Central Valley. Melt-water from the snows of the Sierra Nevada, much of it diverted in lengthy canals, now provides summer irrigation.

Beyond the Central Valley on its western side rise the comparatively low Coast Ranges, running parallel to the Pacific shore all the way from the Mexican border to Canada. Together, the Coast Ranges, the Cascades, and the Sierra Nevada all serve to keep precipitation away from the interior plateaus and create its arid landscape. East of the Cascade Range in the Pacific Northwest lies the Columbia Basin. Here, the meltwaters of ancient glaciers have cut deep gorges in the land. In western Washington the most spectacular trees consist of Douglas fir, western hemlock, and Sitka spruce, some almost as tall as the giant redwoods of northern California. The wealth of the United States' Northwest was originally based on timber from the huge conifers that covered the Cascade Range.

The two non-contiguous parts of the United States have very different physical landscapes. The expansive state of Alaska is a mixture of massive glaciated mountains and broad river valleys, with a vegetation cover that varies from dense forest to sparse tundra. For much of the year large areas of Alaska are covered in snow. The Hawaiian islands mostly consist of the tops of prominent volcanoes which protrude above the sea, with a host of distinctive plants nurtured by the tropical climate.

The first peoples to settle North America probably crossed from Siberia to Alaska during the ice ages between 10,000 and 30,000 years ago. It is thought they became the ancestors of the many Indian tribes living in North America when the first Europeans arrived. Their cultures and languages varied widely, from the Iroquois who lived in bark lodges in the east, to the cliff-dwelling Pueblo peoples of the Southwest, to the salmon-fishing and whale-hunting Indians of Washington State and British Columbia on the Northwest coast who lived in large timber houses. Plains Indians such as the Sioux or the Comanche are sometimes depicted hunting bison on horseback, but this was only possible after horses had been introduced by incoming European traders and settlers from the fifteenth century onward.

The oldest authenticated European settlement in North America was made by Norse Vikings at the northern tip of the island of Newfoundland about ad 1000, but it was occupied for only a short time. The first successful English settlement was at Jamestown, Virginia, in 1607. Not long after this a party of religious dissenters, the so-called Pilgrim Fathers, arrived in 1620 to found the first of the New England colonies at Plymouth. Joined by other migrants later, this became part of the large Massachusetts Bay colony.

A Dutch colony on Manhattan Island that was founded in 1624 was captured by the British in 1664, who changed its name from Nieuw Amsterdam to New York. The Quaker William Penn founded one of the more successful of the early English colonies in 1682. Part of Pennsylvania later split off to become Delaware; North and South Carolina were established in 1663; Georgia, which was originally designed as a philanthropic alternative to a debtor's prison, in 1732. The defeat of the French, which ended the Seven Years War in 1763, brought huge territorial accessions to England: all of France's Canadian territories, the land west of the Mississippi River, plus Louisiana and Florida. The settlers throughout these areas became directly subject to the British Crown, and when London sought to recoup the huge expenses of the war (about <? 101,500,500) by imposing taxes, the cry of "No taxation without representation" was raised in Boston, and resistance to England began. When the American War of Independence broke out in 1776 George Washington commanded the rebel troops, and when it was won and the first elections were held in 1788 he became the inaugural president. In the aftermath, tens of thousands of British "loyalists" decided to leave and moved north to Canada.

The British government had forbidden westward expansion beyond the mountains of the Appalachians. After independence, however, this took place with a rush. Indian tribes were quickly dispossessed from the area and exiled, their land taken for farms, and throughout the nineteenth century there was a series of wars in the region to crush resistance. The last armed Indian defiance was crushed with the Ghost Dance Uprising of 1890.

But by far the most serious crisis for the new nation was the American Civil War of 1861 to 1865. This was both a clash of ideals (liberty versus servitude) and of ways of life (the industrializing, modern north versus the more traditionla, agrarian south). Led by the eloquent commonsense of Abraham Lincoln, the northern forces of the Union defeated the southern armies of the Confederacy, but the legacy of bitterness lasted for many decades and is still palpable at times in the South.

Meanwhile, westward expansion proceeded apace. Pioneers followed trails explored by men such as Meriwether Lewis and William Clark. Railroads spanned the continent, coal and iron were discovered and used, and new cities such as Pittsburgh and Chicago grew up in the interior. European migrants pouring in through the ports of Boston, Philadelphia, and New York substantially changed the nation's ethnic composition. Manufacturing cities, which were big markets in their own right, developed along the shores of the Great Lakes, while the mechanized farming of the Midwestern "corn belt" turned it into the granary of much of the Western world.

The history of California differed from that of the rest of the country in many ways, in that it was a part of Spanish conquest rather than of English settlement. The small, semi-nomadic hunting and seed-gathering Indian cultures of the area were little affected by the northward spread of Spanish forts and missions from New Spain (Mexico) in the 1760s. But by the middle of the nineteenth century pressures from land-hungry pioneers moving in from the eastern states were irresistible: by the end of the century the whole of the Southwest, including Texas, had been either ceded, purchased, or annexed. Since then the Pacific Coast economy has passed through various stages, from gold-prospecting and lumbering, through agriculture and the expansion of the aircraft industry after the Second World War, to the highest of hightech today in Silicon Valley south of San Francisco Bay.

Once independence was established by the beginning of the nineteenth century, the United States kept Europe at arm's length, and the Monroe Doctrine warned Europe that the representatives of the old empires—Spanish, Portuguese, and British—were not to intervene in the Americas any more. Isolationism was the other side of this doctrine: the US had no wish to be entangled in Europe's troubles. But as the US developed into a major global power this disengagement was no longer possible. In two world wars in the twentieth century American military intervention was decisive, and with the onset of the Cold War, designed to contain the Soviet Union after 1945, it was prepared to intervene wherever it saw the need. However, subsequent action in Korea from 1950 to 1953, and in Vietnam from 1964 to 1975, both with heavy loss of US lives, has made the nation less enthusiastic about overseas military commitments and the risks and casualties of policing trouble-spots (Haiti, Somalia, the Persian Gulf) are often unpopular at home. Generally the American mood is inward-looking, more concerned with domestic than with foreign affairs. This, however, changed dramatically after the terrorist attacks on the World Trade Center in New York City and the Pentagon in Washington D.C. on 11 September 2001. Since then the government has pursued the strategy of actively reshaping the world, especially the Middle East, according to American ideals, interests and security concerns. As much opposition as this line of politics encountered in the rest of the world, large parts of the US population supported it, at least until after the toppling of Saddam Hussein's regime in Iraq, which was seen as a threat to stability in the Arab world as well as one of the main supporters of terrorist bands.

The United States is a prosperous, industrial, capitalistic democracy, in which anyone with training and skills who is prepared to assimilate can usually find a place. It is the most open multicultural society on earth, which is the main reason why so many people from other countries want to live there. To keep this in check immense efforts are made to secure the long borders and other entry points into the country such as airports and ports. In addition to tremendous numbers of legal immigrants (the United States still has the highest legal immigration level of any country in the world) illegal entry is estimated to bring in up to 1 million people per year.

The descendants of the original Native American inhabitants are a small but not insignificant element of the population. People arriving from overseas were at first mainly English, and with those of Scottish and Irish descent dominated all other arrivals from the other side of the Atlantic until the middle of the nineteenth