in 1848 after defeating Mexico in a war

the United States annexed these

territories from it and there were many

notable individuals in the U.S that

weren't happy at simply taking these

lands in fact they wanted to manifest

destiny the entirety of Mexico of course

they never did but given how thoroughly

the US won the war this does raise a

question why didn't the U.S take all of

Mexico so the war started after the U.S

Annex Texas and the new borders between

the United States and Mexico became

unclear the Texans and thus now the

Americans claim the border to be here

whereas the Mexican said it was here

both sent troops and after a small

Skirmish the U.S declared war the

Americans won the war handily and so

when it was time to make peace President

James K Polk had a dilemma just how much

land should they take Polk had been

elected on a promise to expand the

United States territorially the war with

Mexico had been contentious domestically

and there were several areas of

disagreement the first was slavery

Mexico had abolished slavery over a

decade before the war but if territory

was taken from it then its status is

either a slave state or a free state

wouldn't be clear those in the South

wanted to play for the practice to

expand to and if all of Mexico could be

turned into slave states then this

future would be secure Polk was himself

pro-slavery but given that his party had

just lost the midterms and the house was

now controlled by the Whig party he had

to compromise the second issue was that

Mexicans were seen as different there

were many U.S politicians who worried

about a sudden influx of

Spanish-speaking non-white Catholics

upsetting life there the third issue was

one of practicality Polk had promised a

quick war against an inferior enemy

which would give Americans lots of free

land as the war had dragged on and

American troops had to move further and

further into Mexico even occupying its

capital this was no longer the case as

such incorporating all of Mexico would

have led to a long and expensive

Guerrilla War those on the opposing side

including future President James I guess

it's okay if you secede Buchanan wanted

all of Mexico their arguments were that

the U.S could handle any Insurgency

similarly to how they had handled the

Native Americans before this they also

argued that all of Mexico should be

annexed on financial grounds Mexico's

Northern Territories were somewhat

Barren whereas The South was much more

arable and would allow the US Navy

access to Southern ports further

expanding its reach it was also believed

that annexing all of Mexico would make

up for the cost of the war so why did

the Lesser annexation plans win out well

it was mostly down to a man called

Nicholas tryst trist was sent to

negotiate a pea settlement and Polk had

ordered him to obtain these territories

trist was largely seen as being too

pro-mexican by the Army and so Polk

fired him the problem was that tryst

simply ignored him and then negotiated a

lesser settlement anyway he did this

because he opposed the war and didn't

believe that America could be both a

republic and an Empire he presented this

lesser treaty to an unhappy president

who just wanted everything over with at

this point Polk had hoped that this

lesser treaty would be signed off by a

hostile house this worked and despite

most Americans actually wanting more of

but not all of Mexico America only

annexed this