ABriefIntroductionTheUnitedStatesofAmerica(commonlyreferredtoastheUnitedStates,theU
,theUSA,orAmerica)isafederalconstitutionalrepubliccomprisingfiftystatesandafederaldistrict
ThecountryissituatedmostlyincentralNorthAmerica,whereitsforty-eightcontiguousstatesandWashington,D
,thecapitaldistrict,liebetweenthePacificandAtlanticOceans,borderedbyCanadatothenorthandMexicotothesouth
ThestateofAlaskaisinthenorthwestofthecontinent,withCanadatoitseastandRussiatothewestacrosstheBeringStrait
ThestateofHawaiiisanarchipelago(群岛)inthemid-Pacific
Thecountryalsopossessesseveralterritories,orinsular(海岛的)areas,scatteredaroundtheCaribbeanandPacific
ABriefIntroductionAt3
79millionsquaremiles(9
83millionkm²)andwithabout305millionpeople,theUnitedStatesisthethirdorfourthlargestcountrybytotalarea,andthirdlarges