Manifest Destiny and Westward Expansion

The concept of Manifest Destiny was central to the expansion of the United States in the 19th century. This lesson explores why Americans believed it was their God-given right to expand westward, and the consequences of that belief for millions of people. This topic forms a key part of the AQA GCSE History specification on America, 1840–1895.

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What Was Manifest Destiny?

Manifest Destiny was the widely held belief that American settlers were destined by God to spread across the North American continent from the Atlantic to the Pacific Ocean. The phrase was first used by journalist John L. O'Sullivan in 1845, but the idea had been growing for decades.

Key beliefs behind Manifest Destiny included:

• Divine right — God had chosen the American people to civilise the continent.
• Racial superiority — Many white Americans believed they were racially and culturally superior to Native Americans and Mexicans.
• Democracy and liberty — Expansion would spread the ideals of freedom and self-government.
• Economic opportunity — The West offered cheap or free land, timber, gold, and furs.

Exam Tip: When asked about the causes of westward expansion, always link Manifest Destiny to both ideological beliefs (God, democracy) and practical factors (land, wealth). Examiners reward answers that show multiple causes.

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Key Dates in Early Expansion

Date	Event	Significance
1803	Louisiana Purchase	The US doubled in size by buying land from France for $15 million
1830	Indian Removal Act	Authorised the forced removal of Native Americans from the eastern states
1836	Texas Independence	Texas broke away from Mexico and later joined the US in 1845
1842	Oregon Trail	Mass migration westward began along the 2,000-mile trail
1845	Annexation of Texas	Texas officially became a US state
1846–1848	Mexican–American War	The US gained California, Nevada, Utah, and parts of other states
1848	Treaty of Guadalupe Hidalgo	Mexico ceded vast territories to the US

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The Oregon Trail

The Oregon Trail was approximately 2,000 miles long, stretching from Independence, Missouri to Oregon City, Oregon. It became the main route for settlers heading west from the early 1840s.

Why Did People Travel West?

Push Factors (reasons to leave the East)	Pull Factors (reasons to go West)
Overcrowding in eastern cities	Cheap or free land (e.g. Donation Land Act 1850)
Economic depression after the 1837 Panic	Fertile farmland in Oregon
Religious persecution (e.g. Mormons)	Discovery of gold in California (1848)
Poor harvests and low wages	Opportunity for a fresh start

Dangers of the Journey

Settlers faced enormous risks on the trail:

• Disease — Cholera was the biggest killer, spreading rapidly through wagon trains.
• Harsh terrain — Crossing the Rocky Mountains was extremely dangerous, especially in winter.
• Starvation — Journeys took 4–6 months, and food supplies often ran low.
• Conflict with Native Americans — Although less common than Hollywood films suggest, clashes did occur.

Exam Tip: The story of the Donner Party (1846–47) is a useful case study. Trapped by snow in the Sierra Nevada, many died of starvation and survivors resorted to cannibalism. Use this to illustrate the extreme dangers of westward migration.

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The Impact on Native Americans

Westward expansion had devastating consequences for Native American peoples. Their lands were taken, their way of life was disrupted, and treaties were routinely broken by the US government.

• The Indian Removal Act (1830) forced the Cherokee, Choctaw, Creek, Chickasaw, and Seminole nations to relocate west of the Mississippi River on the Trail of Tears, during which approximately 4,000 Cherokee died.
• As settlers moved onto the Great Plains, the traditional hunting grounds of nations such as the Sioux and Cheyenne were encroached upon.
• The US government signed and then broke numerous treaties, pushing Native Americans onto smaller and smaller reservations.

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Key Figures

Person	Role
John L. O'Sullivan	Coined the term "Manifest Destiny" in 1845
James K. Polk	President 1845–1849; oversaw the Mexican–American War and the annexation of Texas and Oregon
Brigham Young	Led the Mormons to the Great Salt Lake in 1847
Andrew Jackson	President who signed the Indian Removal Act in 1830

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Summary

Manifest Destiny was a powerful idea that drove the expansion of the United States across the entire continent. It was rooted in a mixture of religious belief, racial attitudes, economic ambition, and political ideology. While it brought enormous opportunity for white American settlers, it came at a devastating cost to Native American nations and to Mexico.

Exam Tip: A common 12-mark question might ask: "Manifest Destiny was the main reason for westward expansion." How far do you agree? Make sure you discuss Manifest Destiny alongside economic factors, government policy, and events like the Gold Rush.