1. The War with Mexico

2. Americans Support Manifest Destiny
Dispute over Oregon: conflict with Britain.
Polk, when running for president, made manifest destiny part of his campaign. Once elected, it became an official government policy.
In 1846, Oregon Territory was split in half.

3. Troubles with Mexico: in 1845, Texas admitted as a slave state.
But because Mexico still claimed Texas for itself, it viewed this as an act of war.
Plus, Texas and Mexico couldn’t agree on the border line.
Polk sends John Siddell (a Spanish-speaking ambassador) to offer $30 million for Texas, New Mexico, and California. But diplomacy fails

4. War Begins
Polk purposely orders General Zachary Taylor to station 3,500 soldiers in the disputed territory.
Polk Urges War: April 25, 1846 – Mexican unit ambushes American patrol… 2 days later, Congress declares war.

5. California
In Northern CA, Americans staged a revolt, raising a flag with a grizzly bear on it. The Bear Flag Revolt declared independence and created the Republic of California.
Troops joined the rebels  all of CA under U.S. control in a few weeks
Fighting in Mexico: fought long and hard, but Mexico City fell Sept. 1847

6. Effects
From Sea to Shining Sea: February 1848, war officially ends with the Treaty of Guadalupe Hildalgo. In the treaty, Mexico: -recognized Texas as part of the U.S Rio Grande River = border between the 2 countries -gave up a vast region known as the Mexican cession
U.S. aggress to protect Mexicans living in U.S. lands
In 1853, Mexico sells more land, called the Gadsden Purchase, for $10 million America now transcontinental!!