USA

The United States of America is a country located in North America, bordered on the west by the Pacific Ocean and to the east by the Atlantic Ocean. Along the northern border is Canada and the southern border is Mexico. The United States of America is the world’s third-largest country in size and nearly the third largest in terms of population. The major characteristic of the United States is probably its great variety. Its physical environment ranges from the Arctic to the subtropical, from the moist rain forest to the arid desert, from the rugged mountain peak to the flat prairie. The United States is the world’s greatest economic power in terms of gross domestic product (GDP) with less than 5 percent of the world’s population, the United States produces about one-fifth of the world’s economic output.

Immigration has been a major source of population growth and cultural change throughout much of the United States history. Immigrants make up significant shares of the U.S. workforce in a range of industries, farming, fishing, and forestry workers—as well as those working in technology and sciences. The United States provides visas for immigrants based on family ties, employment, adoption, special immigrant categories, and student visa.