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Manifest Destiny Overview

Oct 19, 2025

Overview

This lesson explores Manifest Destiny, the 19th-century belief that the United States was destined to expand across North America, and its social, political, and territorial impacts.

Definition and Origins of Manifest Destiny

  • Manifest Destiny was the belief that the U.S. had a God-given right to expand westward across the continent.
  • The term was first used in the 1840s during westward expansion debates.
  • This ideology was used to justify acquiring new territories.

Political and Social Impacts

  • Manifest Destiny influenced U.S. policies, including the annexation of Texas and the Oregon Trail migration.
  • The belief contributed to the Mexican-American War, resulting in the U.S. acquiring California and the Southwest.
  • Native American tribes were forcibly removed or faced violence during expansion.

Arguments for and Against Expansion

  • Supporters claimed expansion spread democracy and civilization.
  • Opponents argued it led to war, displacement, and violated Native and Mexican rights.

Key Events Linked to Manifest Destiny

  • The Louisiana Purchase doubled the size of the U.S. in 1803.
  • The Texas annexation added vast land in 1845.
  • The Gold Rush of 1849 encouraged mass migration to California.

Key Terms & Definitions

  • Manifest Destiny — the belief that U.S. expansion across North America was justified and inevitable.
  • Annexation — the act of adding territory to a country.
  • Mexican-American War — 1846–1848 conflict between the U.S. and Mexico, eventually leading to U.S. control of the Southwest.
  • Oregon Trail — a major route used by settlers moving westward.

Action Items / Next Steps

  • Review textbook sections on Manifest Destiny, the Mexican-American War, and westward expansion.
  • Complete assigned questions on the impact of Manifest Destiny on different groups.