The United States of America is situated on the continent of North America; it spans a geographic area of more than 9.1 million square kilometers (3.5 million square miles). It has widely varied geographic characteristics, from the Great Lakes region of the northern parts of the nation to the Rocky Mountains in the West. The central Great Plains states serve as the agricultural "breadbasket" of the nation. The East Coast borders on the Atlantic Ocean, whereas the West Coast borders on the Pacific Ocean and the South borders on the Gulf of Mexico. Canada is located across the northern border of the nation, and Mexico abuts the nation to the Southwest. The nation also includes the states of Alaska, which lies in in the extreme Northwest of the continent, and Hawaii, a set of islands in the Pacific.

The population of the United States in 2004 was estimated to...