In 1844J amesK. Polk was electedPr es ide nt o f the
UnitedScares.Polkbelievedstrongly in manifest
desti ny .In thespeechat the starto f his
preside ncy- h is"inaugural"add ress- he said that the
Americanclaim "toth ewholeo f Oreg on is clear and
unquestion able. " For a timewar seemedpossible.
But bythesummerof1846 theUnited States was
alread yatwarwithMexico .InJunePolkagreedto
d ivid e OregonwithBritain intwoalmostequal
sectio ns.Thedividinglinewasthe 49th parall el
otlatirudc. whichalreadyfo rm edtheboundary
betweentheUnitedStaresand Canadatoth e castof
theRock yMountains.
T he 1846 warwithMexico had grownoutofevents
that had beentakingplacein T exas.T ho usand sof
Americansh adsettledin Texas,butup tothe18.30sit
wasruledbyMexico. The Te xas Americans.or
T exan s,cametodislikeMexicanru le.InOctober
183 5.theyrebe lled .LedbyGeneralSam Ho usto n,
theyd efeatedamuchlarge rMexicanarmyin 1836at
the BarrieofSanJacimoandmadeT e xas an
indepe ndentrepublic.
li mm ostTexansd idnotwanttheir indepen de nce to
beperm an ent .T heywantedtheircountry toj a m the
U nited Stares.Eventuallythetwocoun t riesreached
an agreementaboutthis andin 1845 Texa sbecam e
part of theUnited Stares.
InApril 1846 , th ere wasfigh tin gbetweenAmerican
andM exi cansoldiersalongthe borde rb etw een
TexasandM exico .P res identPo l k sawan
opportunitytotake land fromM exi co an dhe
dccl.ucdwar.A merican so ldiersinv adedMex icoan d
defeatedthe M exican army.By September 1847 ,
theyhadoccupiedM exi co City,lilt,co unt ry 's capital.
T heM exi ca n - AmericanWar\';\ Sendedb y a peace
treatysignedinFebr ua ryIl::l4KT hetreatyforced
Mexicotohandover eno rmo us stretchesofits
territorytoth e U nitedSta tes.Tod ayth eselands
formth e Amer icanstateso f Cali fornia. Arizo na,
Neva d a. U tah.New Mexico and Co lo rado.
T he annexationofth eseM exican landscomp leted
the"manife stdestiny"oftheUnitedStares.itnow
stretchedacrosstheNorthAmericancon tinent fro m
oceantoocean.In littlemorethan half a cen t ur yit
had grownfro ma small nationon the shoreso f t he
Atlantic intooneofthelargestcountries in th e
world.
')Yl.\ ~ ~0 1GROWTHWagontrains
M ostofthesettlers w hotraveledtoO regon mad e
thej o urn eyin fou r-wheeledwagons. Ag ro u pof
these wagons rravclmg togethe r was called a
"wago n train." Awagon tr ain usuallyco nsistedof
abouttwenty- five w ago ns , each w ith a canv as
cover to prot ect itscont en ts fro m the weather.
Seen from a d istance, these covers m ad e th e
wagons loo klikeshipssailingacrossJ.sea of g rass.
Bec auseo f this, people often called wagons
"prairie schooners." Aschoone r was atypeo f
sailingsh ip.
Each wagon cou ldca rrya loadofbetween 2 and
2 V2to ns and wasp ulledbya teamo f eithe rmules
o r o xen. Settlers argued fi ercely about which
an imals were better. Some claime d that mules
w ere faster andtoughe r than oxen.O thersargued
th at oxenwerestro nge r thanmulesandeasierto
conrrol. So m epeoplebelievethatthe ph rase"as
stu b bo rnas amule"becamepartofth e En glish
languag eat thistime.
Costusu ally settledthe arguments.Asettler coul d
buy thr ee oxen fo rth e priceofo nlyo nemule.Fo r
this reason o xen wereusedmarcth anany o the r
ani mals to pull the wagons that traveled th e
O regon T rail.43