The Louisiana Purchase

Manifest Destiny and Westward Expansion

• James K. Polk was focused on expanding the U.S. and used Manifest Destiny to justify several policies.

The Oregon Treaty of 1848

• The Oregon Treaty of 1848 brought the Oregon Territory under U.S. control.

The Mexican-American War

• The driving force behind the Mexican-American War, which began in 1846, was the idea of Manifest Destiny.
• As a result of the war, the U.S. gained approximately 529,000 square miles of land.

The California Gold Rush

• The California Gold Rush, which started in 1848, helped drive Western expansion.

Promoters of Westward Expansion

• People who tried to convince others to move West were called "boosters."

Native American Relocation

• Many Native American tribes had already been forced to move from the Southeast before being pushed further out West.
• Some Americans believed Native people should sell or give up their land.

Opposition to Manifest Destiny

• The primary opposition to Manifest Destiny among some Americans was that it would lead to the extension of slavery.

Westward Migration

• Approximately 400,000 Americans moved out West in just the first half of the 19th century.

The Louisiana Purchase

• The Louisiana Purchase was made by Thomas Jefferson.
• The Rocky Mountains marked the western boundary of the Louisiana Purchase.
• Meriwether Lewis and William Clark led the Lewis and Clark Expedition to explore the territory.
• A government was created for the Louisiana Purchase territory in 1804.

The Oregon Trail

• The primary route used by settlers moving west from the mid-1830s to 1869 was the Oregon Trail.

The Idea of Manifest Destiny

• The idea behind Manifest Destiny was that the U.S. was destined to expand its territory across North America.
• John O'Sullivan first used the term "Manifest Destiny" in 1845.
• The primary motivation behind Manifest Destiny was the idea of American imperialism and the spread of democracy.
• The Louisiana Purchase added approximately 828,000 square miles of land to the U.S.
• The Rio Grande marked the southern boundary of the Louisiana Purchase.