the United States of America

UNITED STATES (OF AMERICA), THE, the foremost nation of the western hemisphere in the number and wealth of its people, and the second largest in area. It is situated advantageously in the temperate zone of the North American continent (25° 35' to 49° N. lat.), and extends in a broad belt from the Atlantic ocean on the east to the Pacific ocean on the west (66° 55' to 124° 45' W. long.). On the north it is bordered by the Dominion of Canada, the boundary in the west being an arbitrary line at the 49th parallel and in the east largely a natural one formed by the Great Lakes. The eastern half of the southern boundary is naturally defined by the Gulf of Mexico, but in the west the nation is separated from the Republic of Mexico by an oblique line following first the Rio Grande river and continuing afterwards generally west-north-west across the highlands to the Pacific ocean. The eastern coast is separated from Europe by approximately 3,00o miles of the Atlantic ocean which acts as a carrier for an enormous commerce between the two continents, but which, at the same time, gives the United States a degree of isolation from European affairs which has been welcomed and which has con tributed greatly to its independent growth and progress. The Pacific ocean which separates the United States from the Oriental nations of the Far East is wider, varying from 5,0o0 to 6,000 miles, but in the Hawaiian Islands (q.v.) the United States has acquired possession of an important midway stepping stone.

The United States consists of 48 separate and theoretically sov ereign States which are joined together by a Federal Government to which the original 13 States delegated certain powers as out lined in the Federal Constitution adopted in 1787 and put in force in 1789. The official name "The United States of America" is in general usage shortened to "United States," the term being used in the singular instead of a plural sense. The total area of the nation is 3,026,789 sq.m. Its population in 1920 was 105,710,620, or 35.5 per sq.m. Of this number 89.7% was white and chiefly of European origin. In 1930 the population was 122,775,046 or 41.3 per sq.m. In addition there are outlying possessions with a total area of 711,606 sq.m. and a population in 1930 of 14,233,389. (For these possessions see ALASKA, HAWAIIAN ISLANDS, PHIL IPPINE ISLANDS, PORTO RICO, GUAM, VIRGIN ISLANDS, etc.)

The article which follows is divided into these sections: Physical Geography.

Geology.

Climate.

Fauna and Flora.

Population and Social Conditions.

National Finance.

Industry and Commerce.

Defence.

Constitution and Government.

Plan of Relief.

The primary features of the United States are : (a) a vast western highland covering a full third of the country, dominated by mountains of which the general trend is a little west of north, (b) a smaller and lower eastern highland south of the St. Lawrence river, trending north-east—south-west, roughly parallel to the Atlantic coast, (c) a broad interior plain sloping southward and interrupted by the smaller interior high land, and (d) a lowland belt bordering the Atlantic and the Gulf of Mexico.

Major Physiographic Divisions.

The eight major divisions are as follows, the order being determined by the numbering of the physiographic provinces on the map (p. 72o) and in table pages 721 and 722: A,—the Laurentian Upland covers most of eastern Canada and only a small part of the United States south of Lake Superior ; B,—the Atlantic Plain embraces the Atlantic and Gulf coastal plains ; C,—the Appalachian Highlands extend from the St. Lawrence south-west to the Gulf coastal plain with an average width of 30o miles. D,—the Interior Plains are bor dered east and west by the great highlands of the continent and partly enclosed on the north by the Laurentian highland, but west of that they extend north to the Arctic ocean. On the south these Interior plains give way to the Gulf coastal plain but not without a distinct descent. E,—the Interior Highlands are surrounded by plains, the Interior plain on the west and north, and the Gulf coastal plain on the east and south. F,—the Rocky Mountain System enters the United States from Canada and extends south to latitude 36°. This system carries the main continental divide and, while not bearing the highest peaks, affords the greatest mass of land at high levels on the continent. G,—the Intermon tane Plateaux west and south of the Rocky mountain system, occupy approximately half a million square miles, most of it at high altitudes and half of it ribbed by mountains. H,—the Pacific Mountain System occupies a strip about 200 m. wide along the Pacific coast, embracing several distinct ranges and important valleys. See map, page 72o and table, page 721.