United States Geography

I

Introduction

United States Geography, study of the land, physical features, and climate of the United States of America, and the interaction between these natural features and the plants, animals, and people that live in the country.

The United States of America is a federal republic on the continent of North America. It has an area of 9,826,630 sq km (3,794,083 sq mi) and is the third largest country in the world after Russia and Canada. The estimated U.S. population for the year 2007 is 301,139,950, third in the world behind China and India.

The United States consists of 48 contiguous states and the noncontiguous states of Alaska and Hawaii. In addition, the United States includes a number of outlying areas, such as the Commonwealth of Puerto Rico and the Virgin Islands of the United States, which are located on the Caribbean Sea, and the islands of American Samoa and Guam, located in the Pacific Ocean. The national capital is Washington, D.C., located along the banks of the Potomac River between the states of Maryland and Virginia.

The 50 U.S. states vary widely in size and population. The largest states in area are Alaska at 1,717,854 sq km (663,267 sq mi), followed by Texas, and California. The smallest state is Rhode Island, with an area of 4,002 sq km (1,545 sq mi). The state with the largest population is California (36,457,549, 2006 estimate), followed by Texas, and New York. Only 515,004 people (2006 estimate) live on the plateaus and rugged mountains of Wyoming, the least populous state.

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Each state is subdivided into counties, with the exception of Louisiana, where comparable political units are called parishes. Within these counties and parishes, there are communities that range in size from small villages to towns to cities. Extensive areas of urban sprawl exist in larger metropolitan areas such as Los Angeles, California; Chicago, Illinois; and New York City.

This is one of seven major articles that together provide a comprehensive discussion of the United States of America. For more information on the United States, please see the other six major articles: United States (Overview), United States (People), United States (Culture), United States (Economy), United States (Government), and United States (History).

II

An Expansive and Diverse Nation

A

Cultural Diversity

The United States is certainly one of the most diverse countries of the world, both from a cultural and an environmental perspective. The land that is now the United States was home to diverse cultures when the first Europeans and Africans arrived. It was inhabited by a variety of Native American peoples who spoke more than 300 different languages. The Europeans and Africans added their own varying cultures to this diversity.

The 13 colonies they founded along the eastern seaboard became the United States in the late 18th century. see United States (History). During the following century, the new nation added huge chunks of territory, and millions of immigrants arrived, mainly from Europe and especially during the years from 1860 to 1914. A second migration occurred in the Southwest, where Hispanics pushed northward from Mexico, leaving an indelible imprint. see Immigration. In addition, slaves were brought from Africa to work on agricultural estates in the South, where they formed a large percentage of the population. see Slavery in the United States.

Of those who chose to come to the United States, many saw it as a land of plenty, and certainly that was true. However, many Americans faced extraordinary hardships as they adapted to a natural and cultural environment that was sometimes harsh and demanding.

B

Geographic Diversity

During the settlement of the nation, immigrants moved westward across the United States and found a rich and varied natural environment. From the original coastal colonies, settlers made their way over the Appalachian Mountains beginning in the 1700s. Beyond the mountains lay the vast rolling territory drained by the Mississippi River and the Great Lakes. There settlers encountered the rich farmlands of the Ohio Valley, the Mississippi Delta, and the Great Plains. For decades, the rugged peaks of the Rocky Mountains and the arid landscape of the Southwest discouraged movement further west. In the mid-1800s, however, spurred by the discovery of gold in California, determined settlers followed trails through the mountain passes to reach the West Coast. In the valleys of California and Oregon, they found productive agricultural land, and they began harvesting the timber reserves from the untouched forests of the Pacific Northwest. The purchase of Alaska in 1867 added a mountainous northern territory rich in natural resources. The annexation of Hawaii in 1898 gave the United States what would be its only tropical state. The United States has been blessed with many natural advantages, such as climates favorable for agriculture, extensive internal waterways, and abundant natural resources.

All four of the world’s most productive agricultural climates are found in the United States. These climatic regions display a favorable mix of rain and sun as well as a long growing season, and together, they cover more than a third of the country. Favorable climates have allowed farmers to produce vast quantities of grain for human consumption and crops to feed animals. These remarkable climatic areas make the United States one of the world’s leading agricultural countries.

Another major natural advantage—one that is taken for granted by most Americans—is that the major river systems (the Mississippi, Missouri, Ohio, Colorado, and Río Grande systems) flow south. If these rivers flowed north, as rivers do in Russian Siberia, ice and frozen soil would block the meltwater, causing floods that would saturate the land and render it unusable for agriculture. Instead, when spring thaws arrive in the interior mountains of the United States, meltwater flows unimpeded through the river systems to the warm waters of the Gulf of Mexico or the Gulf of California. This almost uninterrupted flow of water provides ample supplies for drinking water and for crop irrigation and industrial production.

The United States has many other natural advantages. A wide array of valuable mineral resources, such as oil, natural gas, iron ore, coal, lead, zinc, phosphate, silver, and copper, benefits mining and industry. The shallow waters along the coastline, known as the continental shelf, serve as a rich breeding ground for marine life, which promotes commercial and sport fishing. The comprehensive network of rivers also provides transportation routes for bulk cargo and the potential for the development of hydroelectricity.

C

Americans and the Environment

The people of the United States used this remarkable array of natural resources to build their society. At first, and for many years, the United States was primarily an agricultural society. Until the second decade of the 20th century, most Americans lived and worked on farms. Rich agricultural land allowed Americans to produce, process, and deliver enough food, not only for the United States, but also for millions of people in other countries.

Americans developed the land’s natural resources in many other ways as well. They used water from the nation’s vast river systems to irrigate arid land and to transport people and goods. They built harbors for ports along the coastlines in order to ship and receive goods from all over the world. They exploited the forests and the fisheries, building major industries providing goods for domestic consumption and for export.

Industry developed early in the United States. During the first half of the 19th century, the Industrial Revolution spread from Europe and stimulated the rapid growth of industry in the Northeast. Raw materials were brought to the Northeast from other parts of the country by ship and by a rapidly expanding rail system. Industrial plants processed the raw material into finished products for export and for domestic consumption.

From 1850 to 1920, industrial expansion continued and moved westward. Chicago, Illinois, became the leading meatpacking center of the United States. Pittsburgh, Pennsylvania, became synonymous with steel. Detroit, Michigan, emerged as the automobile capital of the world. Other large U.S. cities developed their own specialties. By the beginning of World War I (1914-1918), America had become the world’s greatest industrial giant. see United States (History).

However, as Americans developed the land and its resources, they sometimes created environmental problems. Forests and natural grasslands began disappearing as early as colonial times (17th and 18th centuries), as settlers converted more and more wilderness into farmland. In the 20th century, urban sprawl and industrial expansion led to pollution of the air and water. A growing population, and its demands for a convenient lifestyle, generated tremendous amounts of pollution and waste. By the mid-1990s, Americans created 2.0 kg (4.3 lbs) of trash per person per day. Often the highest hill around a typical U.S. city consisted of the waste buried at the local sanitary landfill. See also Air Pollution; Water Pollution.

In the last 30 years of the 20th century, however, Americans have become more aware of environmental problems and have begun programs to reduce pollution and conserve natural areas. People also learned to recycle, to reuse resources, and to protect endangered species. See also Conservation.

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