WAR WITH MEXICO
Chapter 9, Section 3
The Annexation of Texas

Many southerners supported annexation because
Texas allowed slavery
 Admitting
Texas to the Union as a slave state would
boost the South’s political power

Other Americans had doubts about admitting Texas
as a state
 Concerned
that US would have to bear Texas debt
 Annexation would spread slavery westward
 Constitution said nothing about admitting an
independent nation to the US
The Annexation of Texas


Texas remained a republic for nine years
James K. Polk won the in 1844 and wanted
annexation
 Mexico
warned the US that if it annexed Texas it
would consider it a declaration of war against
Mexico

March 1845 – Congress passed resolution
annexing Texas to the United States
 Texas
became a part of the US on December 29,1845
Westward Expansion
Tensions between the US and Mexico

Mexico was furious about Texas annexation
 Mexico
still felt like Texas had been unfairly taken from
it by foreigners during the Texas Revolution

Mexico broke off diplomatic relations with the US
after Texas annexation
Polk and Manifest Destiny


March 1845 – Polk becomes
president
Enthusiastic supporter of
national expansion
 Wanted
the land between
Texas and the Pacific Ocean
 However, New Mexico and
California belonged to
Mexico
 Polk thought they should
become part of the US
The Boundary Dispute

Boundary dispute between
Mexico and Texas
Mexico believed it was at the
Nueces River
 US believed it was at the Rio
Grande


Another dispute was over
money

US said Mexico owed US $3
million for the loss of property
and life during Mexico’s fight for
independence against Spain
Slidell’s Trip

Polk sent a special messenger to Mexico
 John
Slidell arrived with a US offer to cancel the $3
million claims against Mexico in exchange for Mexico’s
recognition of the Rio Grande as the boundary
 He was authorized to pay Mexico up to $30 million for
New Mexico and California


No one would consent to meet with Slidell
He recommended to Polk that Mexico be punished
The Mexican-American War

Polk ordered General Zachary Taylor to advance
into the disputed territory between Nueces River
and Rio Grande
 Led


to a small skirmish
Polk used this event to request that Congress
declare war on Mexico
US declared war on Mexico on May 13, 1846
Fighting the War

General Stephen Kearny
 Took
New Mexico quickly
 California – small group of Americans revolted and
forced Mexican leader to sign treaty (Became known
as Bear Flag Revolt)
 June 14, 1846 – Americans declared independent
Republic of California (US took control about a month
later)
 In a matter of months, the US had control of New
Mexico, California and Mexico’s capital (Mexico City)
Results of the War

Treaty of Guadalupe
Hidalgo
 Ended
the Mexican-American
War
 Mexico turned over to the US
the Mexican Cession
 US paid Mexico $15 million
 1853 – Gadsden Purchaseclarified the treaty boundary
and transferred even more
land to the U.S.