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 Purchase- clarified the treaty boundary and transferred even more land to the U.S.