Heimler's History: AP U.S. History - Unit 5 Overview

Time Period: 1844-1877

Westward Expansion
- Expansion westward was a dominant American impulse at the end of the 18th and first half of the 19th century.
- Initial expansion west of the Atlantic Coast, then into the Ohio River Valley, Louisiana Purchase.
- Defined by John O’Sullivan in 1845 as "Manifest Destiny."

Concept: The belief that Americans had a God-given right to expand from Atlantic to Pacific Oceans.
Justification:
- Extension of liberty and federated self-government.
- It was seen as a divine mission.

Access to Resources
- Discovery of gold in California (1848) leading to California Gold Rush.
- Further discoveries in Colorado, Dakotas, and Nevada.
Economic Opportunities
- Preemption Acts of the 1830s and 1840s: Cheap land for homesteading.
- Migration to the west largely by middle class due to economic means.
Religious Refuge
- Mormons fleeing persecution, especially due to polygamy, settled in the Utah Territory.

Election of James K. Polk (1844)
- Strong proponent of Manifest Destiny.
- Aimed to acquire Texas and Oregon.

Historical Context
- Settled by Americans from the 1820s; part of Mexico.
- Conflict arose due to Mexico's requirements on religion and slavery.
Texas Independence
- Revolt led by Sam Houston in 1836; Battle of the Alamo, Battle of San Jacinto.
- Treaty signed under duress; Mexico did not recognize Texas independence.
Annexation Challenges
- Presidents Jackson and Van Buren refused due to war fears with Mexico.
- Annexation denied by Senate under John Tyler.

Territorial Claims
- Disputed by British and Americans.
- U.S. settlers outnumbered British settlers.
Resolution
- Polk pushed for annexation; agreement reached at 49th parallel.

Texas and Oregon
- Texas annexed during Tyler's presidency; Oregon divided with British.
- Mexican government unhappy with Texas annexation, leading to conflict.

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