Washington,D.C.isthecapitalcityoftheUnitedStatesofAmerica."D.C."isanabbreviationfortheDistrictofColumbia,thefederaldistrictcoextensivewiththecityofWashington.ThecityisnamedafterGeorgeWashington,militaryleaderoftheAmericanRevolutionandthefirstPresidentoftheUnitedStates.ColumbiainthiscontextreferstoChristopherColumbus. 　　ThecityiscommonlyreferredtoasTheDistrictorsimplyWashington.Historically,itwascalledtheFederalCityorWashingtonCity.ToavoidconfusionwiththestateofWashington,locatedinthePacificNorthwest,thecityisoftencalledsimplyD.C.. 　　ThecentersofallthreebranchesoftheU.S.federalgovernmentareintheDistrict.ItalsoservesastheheadquartersfortheWorldBank,theInternationalMonetaryFund,theOrganizationofAmericanStates,theInter-AmericanDevelopmentBank,andothernationalandinternationalinstitutions.Washingtonisthefrequentlocationofpoliticaldemonstrationsandprotests,largeandsmall,particularlyontheNationalMall.Furthermore,Washingtonisapopulardestinationfortourists,thesiteofnumerousnationallandmarksandmonuments.ItisamajorAmericanculturalcenter,withanumberofimportantmuseums,galleries,performingartscentersandinstitutions,andnativemusicscenes. 　　TheDistrictofColumbiaandthecityofWashingtonaregovernedbyasinglemunicipalgovernment,andformostpracticalpurposes,areconsideredtobethesameentity.Thishasnotalwaysbeenthecase.Until1871,whenGeorgetownceasedtobeaseparatecity,thereweremultiplejurisdictionswithintheDistrict.[3]Althoughthereisamunicipalgovernmentandamayor,Congresshasthesupremeauthorityoverthecityanddistrict,whichresultsincitizenshavinglessself-governancethanresidentsofthestates.Inadditiontolackingfullself-governance,theresidentsoftheDistrictalsolackvotingrepresentationinCongress,despitebeingrequiredtopayfederalincometax. 　　ThepopulationoftheDistrictofColumbia,asof2006UnitedStatesCensusBureauestimates,is581,530persons.[1]TheWashingtonMetropolitanAreaistheeighthlargestintheUnitedStateswithmorethanfivemillionresidents,andtheBaltimore-WashingtonMetropolitanAreahasapopulationexceedingeightmillion.IfWashington,D.C.wereastate,itwouldranklastinareabehindRhodeIsland,50thinpopulationaheadofWyoming,firstinpopulationdensity,and35thingrossstateproduct 　　华盛顿城市介绍.