Dr. Pete Ballerstedt is co-author of this informative document.
The United States of America (also referred to as the United States, the US, the USA, or America) is a federal constitutional republic comprising fifty states and a federal district. The country is situated mostly in central North America, where its forty-eight contiguous states and Washington, D.C., the capital district, lie between the Pacific and Atlantic Oceans, bordered by Canada to the north and Mexico to the south. The state of Alaska is in the northwest of the continent, with Canada to the east and Russia to the west across the Bering Strait. The state of Hawaii is an archipelago in the mid-Pacific (see Figure 1.1). The country also possesses several territories in the Caribbean and Pacific (Wikipedia). The 48 contiguous states lie between about latitudes 24–49oN and longitudes 67–125oW. The population estimate for July 2011 was 313 232 044 with a growth rate of 0.963% (World Factbook). The largest city is New York – Newark with a population of 19.3 M; other major cities are Los Angeles, Chicago, Miami and Washington DC. With an area of 3.79 million square miles (9.83 million km2) the USA has land boundaries with Canada of 8 893 km (including 2 477 km with Alaska), and with Mexico of 3 141 km. In terms of total area, the USA is third in the world in size behind Russia and Canada with China fourth.