The United States is the third largest country by land area and by population encompassing 3.79 million square miles (9.83 million km²) and over 300 million people.
The United States consist of 50 states - 48 are called the "contiguous", "continental" or "lower" states. Alaska and Hawaii became the 49th and 50th states of the union. 21 of the smallest U.S. states would fit in to Alaska making it the country’s largest state.
In addition to the states there exist several areas with a special status: Washington D.C. and the US territories of Puerto Rico, the US Virgin Islands, American Samoa, Guam and the Northern Mariana Islands.
Sixteen of the world’s 30 busiest airports are in the United States, including the world’s busiest, Hartsfield-Jackson Atlanta International Airport in Georgia.
In 1872, America’s first national park was established at Yellowstone. Another fifty-seven national parks now preserve the natural beauty and heritage of the nation.