🦬US History – Before 1865 Unit 9 – Manifest Destiny & Western Expansion
Manifest Destiny drove America's westward expansion in the 19th century. This belief in the nation's right to spread across the continent fueled territorial acquisitions, conflicts with Native Americans and Mexico, and rapid settlement of new lands.
The push west reshaped America's boundaries, economy, and identity. It led to the displacement of Native peoples, debates over slavery's expansion, and the transformation of vast territories into new states and economic frontiers.
Manifest Destiny: belief that the United States was destined to expand across the North American continent
Westward Expansion: movement of American settlers into the western territories of the United States during the 19th century
Louisiana Purchase (1803): acquisition of territory from France that doubled the size of the United States
Oregon Trail: 2,000-mile overland route used by settlers traveling from Missouri to Oregon Country
Mexican-American War (1846-1848): conflict between the United States and Mexico resulting in significant territorial gains for the U.S.
Treaty of Guadalupe Hidalgo (1848): agreement that ended the Mexican-American War and ceded vast territories to the United States
Gadsden Purchase (1853): acquisition of land from Mexico that became part of Arizona and New Mexico
Historical Context and Origins
Rooted in the idea of American exceptionalism and the belief in the superiority of American democracy and institutions
Fueled by population growth, economic opportunities, and technological advancements (steamboats, railroads)
Influenced by the Second Great Awakening, which emphasized the importance of spreading Protestant Christianity
Justified by the concept of "Manifest Destiny," a term coined by journalist John O'Sullivan in 1845
Supported by politicians like Andrew Jackson and James K. Polk, who advocated for territorial expansion
Driven by the desire for new agricultural lands, natural resources, and access to Pacific trade routes
Shaped by the idea of the "frontier" as a defining feature of American identity and character
Major Events and Milestones
Louisiana Purchase (1803) doubled the size of the United States and opened up vast new territories for settlement
Lewis and Clark Expedition (1804-1806) explored and mapped the newly acquired Louisiana Territory
Adams-Onis Treaty (1819) established the border between the United States and Spanish Florida
Indian Removal Act (1830) authorized the forced relocation of Native American tribes from the Southeast to the West
Texas Revolution (1835-1836) resulted in the independence of Texas from Mexico
Oregon Treaty (1846) established the 49th parallel as the border between the United States and British Canada in the Pacific Northwest
California Gold Rush (1848-1855) attracted thousands of settlers and accelerated westward migration
Compromise of 1850 addressed the issue of slavery in the newly acquired territories and delayed the onset of the Civil War
Key Figures and Their Roles
Thomas Jefferson: orchestrated the Louisiana Purchase and commissioned the Lewis and Clark Expedition
Meriwether Lewis and William Clark: led the expedition that explored and mapped the Louisiana Territory
Andrew Jackson: advocated for the removal of Native American tribes and signed the Indian Removal Act
Stephen F. Austin: known as the "Father of Texas" for his role in establishing American settlements in Mexican Texas
Sam Houston: led the Texas Revolution and served as the first President of the Republic of Texas
James K. Polk: oversaw the annexation of Texas, the Oregon Treaty, and the Mexican-American War
John C. Frémont: explored and mapped the American West, earning the nickname "The Pathfinder"
Impact on Native American Populations
Westward expansion led to the displacement and forced relocation of numerous Native American tribes
Indian Removal Act (1830) resulted in the Trail of Tears, the forced march of the Cherokee Nation to Indian Territory (present-day Oklahoma)
Treaties were often used to acquire Native American lands, but these agreements were frequently violated or ignored by the U.S. government and settlers
Native Americans faced loss of land, resources, and traditional ways of life as settlers encroached upon their territories
Conflicts and wars erupted between Native American tribes and U.S. forces (Seminole Wars, Black Hawk War)
Reservation system established to confine Native American populations to designated areas
Cultural assimilation policies aimed to eradicate Native American languages, religions, and customs
Territorial Acquisitions and Conflicts
Louisiana Purchase (1803) acquired from France, doubling the size of the United States
Florida acquired through the Adams-Onis Treaty (1819) with Spain
Texas annexed in 1845 after gaining independence from Mexico
Oregon Country jointly occupied with Britain until the Oregon Treaty (1846) established the 49th parallel border
Mexican-American War (1846-1848) resulted in the acquisition of vast territories, including California and the American Southwest
Gadsden Purchase (1853) acquired additional land from Mexico for a southern transcontinental railroad route
Conflicts with Native American tribes (Seminole Wars, Black Hawk War) as settlers encroached upon their territories
Economic and Social Consequences
Expansion of agriculture and the cotton industry in the South, fueled by slave labor
Growth of the mining industry, particularly after the California Gold Rush (1848-1855)
Development of transportation infrastructure (canals, railroads) to connect eastern markets with western resources
Increased sectional tensions between the North and South over the issue of slavery in the new territories
Displacement and forced relocation of Native American populations, disrupting their traditional ways of life
Influx of diverse immigrant populations in the West, including Chinese laborers and European settlers
Growth of cities and towns along the frontier, serving as hubs for trade and commerce
Legacy and Long-Term Effects
Manifest Destiny and westward expansion shaped the geographical boundaries of the modern United States
Acquisition of new territories led to debates over the extension of slavery, contributing to the onset of the Civil War
Displacement and oppression of Native American populations had lasting effects on their communities and cultures
Economic development of the West transformed the nation, providing new resources and markets
Idea of the "frontier" became a central theme in American culture, literature, and identity
Legacy of racial and ethnic diversity in the American West, with lasting impacts on social and political dynamics
Environmental consequences of rapid settlement and resource exploitation, including deforestation and wildlife depletion