1. Mexican Cession & the Mexican American War
(1848)
military conquest

2. War in Texas Mexico = Texas annexation, act of war
No border ever agreed upon (Dispute over Rio Grande)
While patrolling the Rio Grande, American Soldiers killed
Declare war on Mexico

3. New Mexico and California
Polk determined to have California and New Mexico
Areas first colonized by Spain, then became Mexican territories
Both areas fell during Mexican war
Invades Mexico

4. Treaty of Guadalupe Hidalgo
Mexico gives up Texas and Mexican Cession (Half of ALL its territory)
U.S. pays Mexico and promises to protect Mexicans in Texas
A few years later, Gadsden Purchase (1853) – bought from Mexico to complete sw border for transcontinental RR