Federal district of the U.S. Coextensive with the city of Washington , it is bounded by Maryland and Virginia.
Originally 100 sq mi (259 sq km), the territory was authorized by Congress in 1790 and granted by Maryland and Virginia; it now occupies 68 sq mi (176 sq km). The site was chosen by Pres. George Washington and became the seat of the federal government by 1800. Part of the district ( Alexandria , Va.) was retroceded to Virginia in 1847. The slave trade was prohibited in the District in 1850 and slavery was abolished in 1862. The territorial government was abolished in 1874 in favour of government by a commission appointed by the president. Residents were granted suffrage in national elections in 1961 by the 23rd Amendment to the U.S. Constitution . The mayor-council form of government was established in 1967. Originally appointees of the president, the mayor and councilors became elected officials in 1973 and received local legislative powers in 1974.