Download Causes of the Mexican American War

Cause and Effect
The Mexican-American War
Objective : Determining the causes of the Mexican American War
U.S.-Mexico Disputes
• The Annexation of Texas by
the U.S. angered the
Mexican Government.
• Mexico never acknowledged
Texas as independent and
felt the U.S. had no right to
take its territory.
• Mexico also did not
acknowledge the Treaty of
Velasco which set the
southern border of Texas as
the Rio Grande.
• The loss of Texas will inevitably result in
the loss of New Mexico and the Californias.
Little by little our territory will be
absorbed until only an insignificant part is
left to us.... Our national existence... will
end like those weak meteors that, from
time to time, shine fitfully in the
firmament (sky) and disappear. -José Maria Tornel y Mendivil
The U.S. and Texas considered the Rio Grande as the
Southern border. For Mexico it was the Nueces
Area in Dispute
Nueces River
Rio Grande River
• Why would the Mexican government not
accept the treaty of Velasco?
– Santa Anna only signed the treaty of
Velasco because his life was in danger.
Manifest Destiny
• Another issue with Mexico was Manifest Destiny.
• The land that the United States desired out west
(California especially) was all controlled by Mexico.
The U.S. Perspective
• Most Americans sympathized
with Texas during the Texas
revolution and republic days
because most Texans were
former Americans.
• As a result of the brutal
fighting (at the Alamo,
Massacre at Goliad, and
other times) the American
public developed negative
stereotypes against the
Mexican people and
government
Stereotype: A belief that is incorrectly
attributed to an entire group of people
Effort to ease the tensions
• After Texas Annexation,
Mexico threatened war.
• U.S. President James K.
Polk sent John Slidell to
Mexico to work for
better relations
between the two
countries.
John Slidell
Slidell’s Mission
1) Get Mexican recognition of the Rio
Grande as the border between Mexico and
the United States
2) To forgive about $4.5 million owed to
U.S. citizens by Mexico from the Mexican
War of Independence
3) To discuss the purchase of the New
Mexico and California
• The Mexican government refused to talk
with Slidell which angered the U.S.
• A company of U.S. Calvary
The Thornton Affair commanded by Captain Seth
Thornton got into a skirmish
with Mexican forces near the
Rio Grande.
• Thornton was ordered to scout
an area about twenty miles
northwest of what later became
Brownsville, Texas. In April
1846, the Calvary, investigated
an abandoned hacienda
(Ranch).
• Some two thousand Mexican
soldiers were encamped in and
around the hacienda, and a
firefight occurred. Both sides
Thornton was outnumbered
By about 1900 men.
fought ferociously, but the
greatly outnumbered U.S. force
Skirmish: A small battle
was forced to surrender after
several hours of skirmishing.
Presidents Polk’s
Response
• President Polk asked for a declaration of war before a
joint session of the United States Congress, summing up
the need for war by famously stating:
– "American blood has been shed on American soil".
• Congress declared war on Mexico, despite protests by
the Mexican government that Thornton had crossed the
border into Mexican Texas — a border that Mexico
claimed as the Nueces River. the ensuing MexicanAmerican War was waged from 1846-1848 and witnessed
the loss of many thousands of lives and nearly half of
the territory of Mexico.
• US Problems with
Mexico
1) Americans had a
negative view of
Mexico because of
the Texas Revolution
2) Mexico owed the
U.S. money for the
Mexican Revolution
against Spain
• Mexican Problems
with US.
1) Mexico felt that
Texas was being
stolen from them.
2) Mexico didn’t
believe in Manifest
Destiny and didn’t
want to give away
their land.
Vote Yes-Declare War
• Treaty of Velasco is
valid
• Belief in Manifest
Destiny
• Texas Annexation
is legal
Vote no-not to Declare War
• Will expand slavery
• Manifest Destiny is
unfair to Mexico
• Treaty of Velasco is a
sham and not valid
• Annexation is illegal
without Mexico
approval.
POLK’s Speech Video