Back

INTRODUCTION United States of America, popularly referred to as the United States or as America, a federal republic on the continent of North America, consisting of 48 contiguous states and the noncontiguous states of Alaska and Hawaii. Outlying areas include Puerto Rico, American Samoa, Guam, and the Virgin Islands of the United States. The conterminous 48 states are bounded on the north by Canada, on the east by the Atlantic Ocean, on the south by the Gulf of Mexico and Mexico, and on the west by the Pacific Ocean. The northern boundary is partly formed by the Great Lakes and the Saint Lawrence River; the southern boundary is partly formed by the Río Grande. New York City is the largest city in the United States. Washington, D.C., is the capital.

The total area of the United States (including the District of Columbia) is 9,629,047 sq km (3,717,796 sq mi), of which 1,593,440 sq km (615,230 sq mi) are in Alaska and 16,729 sq km (6459 sq mi) are in Hawaii. The total land area of the country is 9,158,918 sq km (3,536,278 sq mi). Inland, coastal, and Great Lakes bodies of water occupy 470,129 sq km (181,518 sq mi) of the total area. Measured along the parallel of latitude that passes through West Quoddy Head, Maine, the easternmost point in the United States, the maximum width of the conterminous 48 states is 4421 km (2747 mi). The maximum length measured from the vicinity of Brownsville, Texas, due north to the Canadian border is 2572 km (1598 mi). The boundaries of the United States extend along the Atlantic and Pacific oceans, along the Gulf of Mexico, and along land areas. The northern boundary is some 6420 km (some 3990 mi) long; the southern boundary, 3111 km (1933 mi); and the boundary between Alaska and Canada, some 2480 km (some 1540 mi). For the United States, the Atlantic coastline is 3330 km (2069 mi) long; the Pacific coastline, including Hawaii, 12,268 km (7623 mi); the Gulf of Mexico coastline, 2625 km (1631 mi); and the Arctic coastline of Alaska, 1706 km (1060 mi). Mount McKinley, or Denali (6194 m/20,320 ft), in Alaska, is the highest point in North America; Death Valley, a depression 86 m (282 ft) below sea level, in California, is the lowest point. The mean elevation of the United States is about 760 m (about 2500 ft) above sea level.
LAND AND RESOURCES The United States has an enormous variety of physical features and a wide diversity of animal and plant life. Besides the discussion below, much information is given in the separate articles on the states, as well as those on important mountains, rivers, lakes, and other physical features.
Geologic History of Physiographic Regions The present-day pattern of the landforms of the United States is the result of a long sequence of collisions and separations of large blocks of the earth's surface crust (see Plate Tectonics). The oldest part of the continent is the Canadian Shield, or Laurentian Plateau, a mass of granite and related rock that underlies eastern Canada and the northeastern United States. The shield was formed during several long periods of crustal convergence in Precambrian time (a period that stretches from the formation of the earth to about 570 million years ago). During these slow but relentless collisions of crustal plates, the rigid surface rocks buckled and cracked. Large pieces of crust were forced downward into the hot interior of the earth, where they warmed and eventually melted. This lighter molten material then moved upward through the crustal cracks, occasionally erupting as a volcano, but more often pushing surface rock upward in a broad bulge, or dome. In time, the molten material cooled and crystallized. The characteristic rock of the shield is granite, a slowly cooled and therefore coarse-grained rock. The margins of the ancient continent are more complex in structure, with zones of granite, darker ocean-bottom rocks, fine-grained volcanic rocks, hardened ocean sediments, and rocks of all types that were altered by heat and pressure during later crustal activity. The iron deposits of Minnesota, Upper Michigan, Wisconsin, and northern New York all occur in contorted rocks near the edges of the ancient shield. A long period of inactivity in the crust followed the formation of the shield. Erosion reduced the mountainous continent to a low plain, and the adjoining seas were filled with thick beds of sediment. Near the end of this period, great forests covered the land, and the addition of organic material to the sediment formed the vast coal and petroleum layers that stretch in a broad curve from northern Pennsylvania through West Virginia to Alabama, then west to Texas and northwest through the Great Plains states and Canadian prairies to Arctic Alaska.
POPULATION

The population of the United States is highly mobile. In the 1980s and early 1990s redistribution from the North Central and Northeast states to the South and West continued to be a major trend, as the American population became increasingly diverse in ethnic composition, characteristics, language, and religion. According to the 1990 census, the resident population of the United States was 248,709,873. The population grew by 22,164,068 people-or 9.8 percent-during the decade from 1980 to 1990. This increase was not evenly distributed: About 12 million, or 54.3 percent of the growth, occurred in the states of California, Texas, and Florida. The 1998 estimated population of the United States was 270,311,758. Another trend evident during the 1980s was that although urban areas grew at a somewhat higher rate than rural areas, growth rates were low in some of the largest metropolitan areas, and the population of a number of major cities-such as Chicago, Philadelphia, and Detroit-decreased substantially from 1980 to 1990.
Language English is the main language of the United States and is spoken by the great majority of U.S. residents. Nearly 32 million U.S. residents age 5 or older speak a language other than English at home. Of this total, approximately 54 percent speak Spanish, making Spanish the second most widely spoken language in the United States. Other languages frequently spoken include Chinese, Tagalog, Polish, Korean, Vietnamese, Portuguese, Japanese, Greek, Arabic, Hindi and Urdu, Russian, Yiddish, Thai and Lao, Persian, French Creole, Armenian, and Navaho.
EDUCATION AND CULTURE In the United States, education, cultural activities, and the communications media exert a tremendous influence on the lives of individuals. Through these means, knowledge and cultural values are generated, transmitted, and preserved from one generation to the next. In most of the United States, illiteracy has been virtually eliminated. However, census estimates suggest that 2.4 percent of the population over age 25 is functionally illiterate, that is, they are unable to read and write well enough to meet the demands of everyday life. More of the population has received more education than ever before. Among Americans aged 25 and older in 1996, 82 percent had completed high school, as compared with only about one-fourth of the population as recently as 1940. In 1996, 24 percent of the population had completed four or more years of college. This same trend toward increased accessibility and usage applies to America's cultural institutions, which have continued to thrive despite a troubled economy.
Education In the United States, education is offered at all levels from prekindergarten to graduate school by both public and private institutions. Elementary and secondary education involves 12 years of schooling, the successful completion of which leads to a high school diploma. Although public education can be defined in various ways, one key concept is the accountability of school officials to the voters. In theory, responsibility for operating the public education system in the United States is local. In fact, much of the local control has been superseded, and state legislation controls financing methods, academic standards, and policy and curriculum guidelines. Because public education is separately developed within each state, variations exist from one state to another. Parallel paths among states have developed, however, in part because public education is also a matter of national interest. Public elementary and secondary education is supported financially by three levels of government-local, state, and federal. Local school districts often levy property taxes, which are the major source of financing for the public school systems. One of the problems that arises because of the heavy reliance on local property tax is a disparity in the quality of education received by students. Rich communities can afford to pay more per student than poorer communities; consequently, the disparity in wealth affects the quality of education received. Some states have taken measures to level this imbalance by distributing property tax collections to school districts based on the number of students enrolled. When public education was established in the American colonies in the mid-17th century, it was viewed by many as an instrument that would break down the barriers of social class and prejudice. Public schools were intended for all creeds, classes, and religions. In addition to the development of individuals, public schools were to promote social harmony by equalizing the conditions of the population. Most students attended private schools, however, until well into the 19th century. Then, in the decades before the American Civil War (1861-1865), a transition took place from private to public school education. This transition was to provide children of all classes with a free education. The idea of free public education did, however, encounter opposition. The nonwhite population, which consisted primarily of blacks, was either totally denied an education or allowed to attend only racially segregated schools.
Higher Education

The first American colleges were small and attended by an aristocratic student body. The earliest institutions were established in the United States between the mid-17th and mid-18th centuries: Harvard University (1636), the College of William and Mary (1693), Yale University (1701), the University of Pennsylvania (1740), Princeton University (1746), Columbia University (1754), Brown University (1764), Rutgers University (1771), and Dartmouth College (1769). These private institutions initially prepared students for careers in theology, law, medicine, and teaching-a curriculum too narrow for a country experiencing a rapid expansion of its territory, industry, and industrial population. An important development occurred in 1862, when President Abraham Lincoln signed the Morrill Act (see Land-Grant Colleges), which donated public lands to the several states and territories to provide colleges with the resources necessary to teach such branches of learning as agriculture and the mechanical arts. The Morrill Act was designed to promote the liberal and practical education of the new industrial population. Based on the act, each state was granted 30,000 acres (12,141 hectares) of federal land for each member it had in Congress. In addition to creating colleges, the Morrill Act extended education to groups that would benefit from higher education regardless of financial background and greatly accelerated the admission of women to institutions of higher learning. Some of the larger institutions that were established or expanded as a result of the Morrill Act include the University of Arizona (1885), the University of California at Berkeley (1868), the University of Florida (1853), the University of Illinois (1867), Purdue University (1865), the University of Maryland (1807), Michigan State University (1855), Ohio State University (1870), Pennsylvania State University (1855), and the University of Wisconsin (1849). Higher education, like elementary and secondary education, has historically been racially segregated in the United States. Before 1954 most blacks gained access to higher education only by attending colleges and universities established for blacks, nearly all of which were located in the southern states. With the gradual dissolution of most traditional racial barriers, more and more blacks enrolled in institutions where whites made up the majority of the student body. By 1995 only 16 percent of all black students were enrolled in the 103 historically black colleges and universities.
Costs of Higher Education The cost of higher education varies by type of institution. Tuition is highest at private four-year institutions, and lowest at public two-year institutions. The private four-year colleges doubled their average tuition rates between 1985 and 1995. For private four-year colleges, tuition and fees for the 1996 academic year averaged about $15,581, compared with $3151 at public four-year colleges. The cost of attending an institution of higher education includes not only tuition and fees, however, but also books and supplies, transportation, personal expenses and, sometimes, room and board. Although tuition and fees generally are substantially lower at public institutions than at private ones, the other student costs are about the same. The average cost for tuition, fees, and room and board for the 1996 academic year at private four-year colleges was $22,469. At public four-year colleges the average combined cost was $7451.


"United States of America," Microsoft® Encarta® Encyclopedia 99. © 1993-1998 Microsoft Corporation. All rights reserved.