Mexican-American War

Mexican-American War

Manifest Destiny - national belief that the United States should expand to claim and settle land all the way to the Pacific

James K Polk campaigned on idea of expansion, including annexation of Texas and expansion into Oregon Territory

Outgoing President John Tyler annexes Texas on last day of his presidency

After Polk’s election, John Slidell is sent to Mexico to negotiate purchase of California and New Mexico. He is authorized to offer 30 million dollars but is rejected without a meeting.

Polk tells General Zachary Taylor to station troops in contested area between Nueces River and Rio Grande (Nueces was border according to Mexico, and Rio Grande was border according to US). His troops are fired upon in month of  April 1846 and President Polk asks Congress for Declaration of War in May of 1846

Americans overwhelmingly support the War, with exception of abolitionists and some Whigs

General Stephen Watts Kearney led forces into California and New Mexico while General Taylor pushed to Mexico City.

In June 1846, John C Frémont proclaimed California as Republic of California -- unaware of war with Mexico. American troops land and claim California shortly thereafter.

By September 1847, General Winfield Scott had captured Mexico City and the war was over.

Treaty of Guadalupe Hidalgo settled claims. Mexico ceded California and New Mexico for 15 million dollars.

War only inflamed controversy over expansion of slavery, with competing proposals to address the issue: Wilmot Proviso proposed forbidding slavery in new territories. The bill was rejected.