District of Columbia (Washington, D.C.) is the capital city of the USA. The White House, the Capitol, the Supreme Court, and many other government buildings are located in Washington, D.C.

President George Washington chose the site as the future capital of the USA in 1791 (the French architect Pierre Charles L'Enfant designed the city). Washington, D.C. became the nation's capital on June 11,1800 (previously, the country had been governed from Philadelphia, Pennsylvania). The first President to live in Washington D.C. was John Adams; his family moved there in 1800.

Postal Abbreviation - DC
Area - 68.25 square miles (176.75 square km) [Washington, D.C. is smaller in area than any state in the USA]
Population - 572,059 (as of 2000) [Washington, D.C. has more people than Wyoming, the least populous state but fewer people than Vermont, the 49th most populous state]
Major Industry - government 

Major Rivers - Potomac River, Anacostia River
Highest Point - Tenleytown - 410 feet (125 m) above sea level
Bordering States - Virginia, Maryland

Origin of the Name Washington, District of Columbia - The name Washington was to honor the first president of the USA, George Washington. The name Columbia is in reference to Christopher Columbus.
Nickname - D.C.
Official Motto - "Justia Omnibus" - Justice for All
Official Song - The Star-Spangled Banner, words by Francis Scott Key

Washington, D.C. Symbols and Emblems:

Flag The flag of Washington, D.C., was adopted in 1938. Since Washington, D.C., had no official flag, a commission was formed in 1920 to find a design. Headed by A. E. Dubois, the final design was chosen on October 15, 1938. The design was based on the shield from George Washington's family's coat of arms.

Official Bird Wood thrush

Official Flower American beauty rose

Official Tree Scarlet Oak