Manifest Destiny: 1830-1850

Chapter 14
Manifest Destiny
• What was it?
• Belief that the United States was “destined” to settle the entire North
American continent from Atlantic to Pacific Oceans
• What caused it?
• Louisiana Purchase—made the possibility of coast to coast settlement
realistic for the first time
• Economic motives—more land to be settled by farmers, lots of natural
resources to be exploited by others
• Racial motives—belief that European Americans were racially superior to
the American Indians/Mexicans who currently occupied the West
• Religious motives—God wanted the US to spread its divinely inspired
government, civilization, and Protestant religion to the uncivilized west
Focus of US Westward Expansion 1830-1848
• Texas, Oregon, California
• American Expansion into Texas 1820-1845
• 1820s Mexico gained its independence from Spain
• 1823 Mexican govt began offering large tracts of land in Texas to American
settlers who agreed to populate the area (Stephen Austin)
• 1835 30,000 Americans living in Texas
• American-Mexican tensions
• Slavery, religion, illegal immigration, local governance
1835 self government for Texas repealed
1836 Independence declared, war for independence 1836
Texas as independent country 1836-1845
Why no immediate US annexation in 1836?
• Didn’t want to anger Mexico, slavery issue
• Became issue in 1844 election
Oregon and California
• Oregon Country
• Area of modern day Oregon, Washington, Idaho, and British Columbia
• Originally claimed by Spain, Britain, US, and Russia—by 1820s only US and
• 1840s American immigration to Oregon increased rapidly
• 1846 5,000 Americans living in Oregon Country, not that many British
• Became election issue in 1844
• California
• California was sparsely populated by Mexican citizens
• Home to lots of good farmland and valuable ports
• US wanted to buy California from Mexico
Politics 1840-1844: Tyler and Polk
• William Henry Harrison (Whig) elected 1840
• John Tyler became President 1841
• President without a party—didn’t get along with the Whigs
• Expelled from the Whig party
• Election of 1844
• James k. Polk (Democrat) “Who is James K. Polk?”
• Expansion: pro-annexation of Texas, pro-annexation of Oregon, pro-annexation of
• Henry Clay (Whig)
• Anti-expansion: build up the land that the US currently has, afraid of the debate
over the spread of slavery
• Polk won by a large margin
• Tyler—annexed Texas in his last weeks in office 1845
Polk Presidency
• Goals of Polk
Annexation Texas—completed by Tyler before Polk took office
Lower tariffs—achieved in 1846
Renew of the independent treasury—achieved in 1846
Annexation of Oregon
• Polk threatened war with Britain, “54-40 or Fight!” (all of modern day British
• Settled at the 49th parallel—modern US-Canada border
• So no 54-40 and no fight either
• Annex California
• Polk wanted to buy California from Mexico, but the Mexicans weren’t selling,
• Polk’s other options?? Take California by force
Mexican American War 1846-1848
• Causes
• Polk wanted to take control of California
• Disputes between US and Mexico over the Texas border
• Mexico upset about US annexation of Texas
• Start of War
Polk sent soldiers to disputed zone between US and Mexico
Soldiers stayed there until Mexicans attacked—several weeks
“American blood on American soil!”
Small but important opposition to the war—conscience Whigs (Abraham
• War Declared 1846
• War 1846-1848
• US quickly conquered California—Fremont, New Mexico—Kearny, and
most of Mexico—Zachary Taylor and Winfield Scott
• Peace treaty—Treaty of Guadalupe Hidalgo (1848)—ended the war
Impact of Mexican American War