Geography of the United States

The term "United States," when used in the geographic sense, refers to the contiguous United States (sometimes referred to as the Lower 48, including the District of Columbia not as a state), Alaska, Hawaii, the five insular territories of Puerto Rico, Northern Mariana Islands, U.S. Virgin Islands, Guam, American Samoa, and minor outlying possessions. The United States shares land borders with Canada and Mexico and maritime borders with Russia, Cuba, the Bahamas, and a few other countries, mainly in the Caribbean, in addition to Canada and Mexico.

Source: Wikipedia — Geography of the United States (CC BY-SA 4.0)