federal district of the U.S., on the N bank of the Potomac River: 61 sq mi (159 sq km); pop. 572,000; coextensive with the city of Washington: abbrev. DC or D.C.
after Christopher Columbus
See District of Columbia in American Heritage Dictionary 4
Abbr. DC or D.C.
A federal district of the eastern United States on the Potomac River between Virginia and Maryland. Coextensive with the city of Washington, it was established by congressional acts of 1790 and 1791 on a site selected by George Washington.