5.2 Manifest Destiny

The idea of Manifest Destiny

Manifest Destiny was the belief, popularized in the 1840s, that the U.S. was destined by God and providence to expand across the continent to the Pacific. It fueled westward migration, territorial acquisition, and justified displacing Native Americans and Mexicans. Supporters saw expansion as spreading democracy, religion, and 'civilization.'

Territorial acquisitions

The U.S. annexed Texas (1845), gained the Oregon Territory (1846 treaty with Britain), and won vast lands via the Mexican-American War (1846-1848), formalized in the Treaty of Guadalupe Hidalgo, adding California and the Southwest. The Gadsden Purchase (1853) added more land. These gains intensified debates over slavery's expansion.

Consequences and controversy

Expansion displaced Native Americans and Mexican Americans, sparking conflict and debates over citizenship rights. It also reignited sectional tensions, as Northerners and Southerners disagreed over whether new territories would allow slavery. Critics like Henry David Thoreau and the Wilmot Proviso movement opposed the war and expansion on moral and political grounds.

Key terms

Manifest Destiny

Belief that the U.S. was destined to expand across the continent to the Pacific Ocean.

Treaty of Guadalupe Hidalgo (1848)

Ended the Mexican-American War; U.S. gained California and the Southwest.

Wilmot Proviso

1846 proposal to ban slavery in territory gained from Mexico; intensified sectional tensions.

Annexation of Texas (1845)

U.S. admitted Texas as a slave state, angering Mexico and contributing to war.

Gadsden Purchase (1853)

U.S. purchase of land from Mexico for a southern transcontinental railroad route.

Try an AP-style question

Manifest Destiny was the belief that…

1. the U.S. should return land to Mexico
2. expansion should stop at the Mississippi
3. Europe should colonize the West
4. the U.S. was destined to expand across the continent