Mexican Cession & the Mexican American War ( ) military conquest

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

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 

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