第2个回答 2016-05-10
TheUnitedStatesofAmerica,alsoknownastheUnitedStates,theU.S.,theU.S.A.,andAmerica,isacountryinNorthAmericathatshareslandborderswithCanadaandMexico,andaseaborderwithRussia.ExtendingfromtheAtlanticOceantothePacificOcean,theUnitedStatesisafederalrepublic,withitscapitalinWashington,D.C.Thepresent-daycontinentalUnitedStateshasbeeninhabitedforatleast15,000yearsbyindigenoustribes.[1]AfterEuropeanexplorationandsettlementinthe16thcentury,theEnglishestablishedtheirowncolonies—andgainedcontrolofothersthathadbeenbegunbyotherEuropeannations—intheeasternportionofthecontinentinthe17thandearly18thcenturies.On4July1776,atwarwithBritainoverfairgovernance,thirteenofthesecoloniesdeclaredtheirindependence.In1783,thewarendedinBritishacceptanceofthenewnation.Sincethen,thecountryhasmorethanquadrupledinsize:itnowconsistsof50statesandonefederaldistrict;italsohasnumerousoverseasterritories.Atover3.7millionsquaremiles(over9.5millionkm2),theU.S.isthethirdorfourthlargestcountrybytotalarea,dependingonwhetherthedisputedareasofChinaareincluded.Itistheworld'sthirdmostpopulousnation,withnearly300millionpeople.TheUnitedStateshasmaintainedaliberaldemocraticpoliticalsystemsinceitadopteditsArticlesofConfederationon1March1781andtheConstitution,theArticles'replacement,on17September1787.Americanmilitary,economic,cultural,andpoliticalinfluenceincreasedthroughoutthe20thcentury;withthecollapseoftheSovietUnionattheendoftheColdWar,thenationemergedastheworld'ssoleremainingsuperpower.[2]Today,itplaysamajorroleinworldaffairs.TheearliestknownuseofthenameAmericaisfrom1507,whenaglobeandalargemapcreatedbytheGermancartographerMartinWaldseemüllerinSaint-Die-des-VosgesdescribedthecombinedcontinentsofNorthandSouthAmerica.Althoughtheoriginofthenameisuncertain[3],themostwidelyheldbeliefisthatexpressedinanaccompanyingbook,CosmographiaeIntroductio,whichexplainsitasafeminizedversionoftheLatinnameofItalianexplorerAmerigoVespucci(AmericusVespucius);inLatin,theothercontinents'nameswereallfeminine.Vespuccitheorized,correctly,thatChristopherColumbus,onreachingislandsintheCaribbeanSeain1492,hadcomenottoIndiabuttoa"NewWorld".TheAmericaswerealsoknownasColumbia,afterColumbus,promptingthenameDistrictofColumbiaforthelandsetasideastheU.S.capital.ColumbiaremainedapopularnamefortheUnitedStatesuntiltheearly20thcentury,whenitfellintorelativedisuse;butitisstillusedpoeticallyandappearsinvariousnamesandtitles.AfemalepersonificationofthecountryisalsocalledColumbia;sheissimilartoBritannia.[4][5][6][7]ColumbusDay,aholidayintheU.S.andothercountriesintheAmericascommemoratingColumbus'October1492landing.Theterm"unitedStatesofAmerica"wasfirstusedofficiallyintheDeclarationofIndependence,adoptedon4July1776.On15November1777,theSecondContinentalCongressadoptedtheArticlesofConfederation,thefirstofwhichstated"TheStileofthisConfederacyshallbe'TheUnitedStatesofAmerica.'"TheadjectivalanddemonymicformsfortheUnitedStatesareAmerican,apointofcontroversyamongsome.本回答被网友采纳