At 9.83 million km2 and with around 315 million people, the United States is the third- or fourth-largest country by total area, and the third-largest by both land area and population. It is one of the world’s most ethnically diverse and multicultural nations, the product of large-scale immigration from many countries. The geography and climate of the United States is also extremely diverse and is home to a variety of species.
[Wikipedia]