THE USA TODAY

National BirdBald Eagle

National FlowerRose

National AnthemStar-Spangled Banner

Declaration of Independence: July 4, 1776

Capital:Washington, District of Columbia (Washington, D.C.)

Origin of Name:the feminine version of the Latin name of Italian explorer Amerigo Vespucci. in Latin, the other continents' names were all feminine.

National Nicknames:the U.S. • USA • the U.S. of A. • the States • America • Uncle Sam

National Mottos: E Pluribus Unum (Out Of Many, One) • In God We Trust

The United States of America (also called the United States, the U.S., the USA, America, and the States) 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. 1507, German cartographer Martin Waldseemüller produced a world map on which he named the lands of the Western Hemisphere "America" after Italian explorer and cartographer Amerigo Vespucci. The former British colonies first used the country's modern name in the 1776 Declaration of Independence, the "unanimous Declaration of the thirteen united States of America". On November 15, 1777, the Second Continental Congress adopted the Articles of Confederation, which states, "The Stile of this Confederacy shall be 'The United States of America'." The Franco-American treaties of 1778 used "United States of North America", but from July 11, 1778, "United States of America" was used on the country's bills of exchange, and it has been the official name ever since.

Science and technology. The United States has been a leader in scientific research and technological innovation since the late 19th century. In 1876, Alexander Graham Bell was awarded the first U.S. patent for the telephone. Thomas Edison's laboratory developed the phonograph, the first long-lasting light bulb, and the first viable movie camera. Nikola Tesla pioneered alternating current, the AC motor, and radio. In the early 20th century, the automobile companies of Ransom E. Olds and Henry Ford popularized the assembly line. The Wright brothers, in 1903, made the first sustained and controlled heavier-than-air powered flight.

The rise of Nazism in the 1930s led many European scientists, including Albert Einstein and Enrico Fermi, to immigrate to the United States. During World War II, the Manhattan Project developed nuclear weapons, ushering in the Atomic Age. The Space Race produced rapid advances in rocketry, materials science, and computers. IBM, Apple Computer, and Microsoft refined and popularized the personal computer. The United States largely developed the ARPANET and its successor, the Internet. Today, 64% of research and development funding comes from the private sector. The United States leads the world in scientific research papers and impact factor. Americans possess high levels of technological consumer goods, and almost half of U.S. households have broadband Internet access. The country is the primary developer and grower of genetically modified food, representing half of the world's biotech crops.