ThomasJefferson(April13,1743–July4,1826)[2]wasthethirdPresidentoftheUnitedStates(1801–1809)andtheprincipalauthoroftheDeclarationofIndependence(1776).JeffersonwasoneofthemostinfluentialFoundingFathers,knownforhispromotionoftheidealsofrepublicanismintheUnitedStates.JeffersonenvisionedAmericaastheforcebehindagreat"EmpireofLiberty"[3]thatwouldpromoterepublicanismandcountertheimperialismoftheBritishEmpire.

　　MajoreventsduringhispresidencyincludetheLouisianaPurchase(1803)andtheLewisandClarkExpedition(1804–1806),aswellasescalatingtensionswithbothBritainandFrancethatledtowarwithBritainin1812,afterheleftoffice.

　　Asapoliticalphilosopher,JeffersonwasamanoftheEnlightenmentandknewmanyintellectualleadersinBritainandFrance.Heidealizedtheindependentyeomanfarmerasexemplarofrepublicanvirtues,distrustedcitiesandfinanciers,andfavoredstates'rightsandastrictlylimitedfederalgovernment.Jeffersonsupportedtheseparationofchurchandstate[4]andwastheauthoroftheVirginiaStatuteforReligiousFreedom(1779,1786).HewastheeponymofJeffersoniandemocracyandthecofounderandleaderoftheDemocratic-RepublicanParty,whichdominatedAmericanpoliticsfor25years.JeffersonservedasthewartimeGovernorofVirginia(1779–1781),firstUnitedStatesSecretaryofState(1789–1793),andsecondVicePresidentoftheUnitedStates(1797–1801).

　　Apolymath,Jeffersonachieveddistinctionas,amongotherthings,ahorticulturist,politicalleader,architect,archaeologist,paleontologist,musician,inventor,andfounderoftheUniversityofVirginia.WhenPresidentJohnF.Kennedywelcomed49NobelPrizewinnerstotheWhiteHousein1962hesaid,"IthinkthisisthemostextraordinarycollectionoftalentandofhumanknowledgethathaseverbeengatheredtogetherattheWhiteHouse–withthepossibleexceptionofwhenThomasJeffersondinedalone."[5]Todate,JeffersonistheonlypresidenttoservetwofulltermsinofficewithoutvetoingasinglebillofCongress.JeffersonhasbeenconsistentlyrankedbyscholarsasoneofthegreatestofU.S.presidents.