5.2 Manifest Destiny

In 1845 the newspaper editor John L. O'Sullivan wrote that it was America's 'manifest destiny to overspread the continent allotted by Providence'. 'Manifest' means obvious, and 'Providence' means God's plan. The phrase captured a belief that expansion was natural, inevitable and blessed by God.

Manifest Destiny combined several ideas: that Americans had a mission to spread democracy and Protestant Christianity; that white Americans were superior to Native peoples and Mexicans; and that the country needed land for its growing population. It was used to justify taking land from Native nations and from Mexico.

• Land: cheap, fertile farmland in Oregon and California drew families, especially after the Panic of 1837.
• Gold and other resources: the California Gold Rush pulled hundreds of thousands of people west.
• Trade: Pacific ports like San Francisco offered access to Asian markets. The Treaty of Wanghia (1844) opened Chinese ports to American merchants, and in 1853–1854 Commodore Matthew Perry's warships pressured Japan into opening two ports to American ships.
• Religious freedom: Mormons, fleeing persecution, migrated to the Great Salt Lake valley in 1847.
• Slavery: many Southerners wanted new land for cotton and slavery, especially in Texas.

After Mexico won independence from Spain in 1821, it invited American settlers into its northern province of Texas; Stephen F. Austin brought the first colonists. By the 1830s Americans, many of them Southerners who brought enslaved people, far outnumbered Mexicans there. They resented Mexico's efforts to enforce its laws, including its 1829 abolition of slavery, and its move toward a stronger central government under Antonio López de Santa Anna.

In 1835–1836 Texans revolted. Santa Anna's army destroyed the defenders of the Alamo in March 1836, but Sam Houston's army defeated and captured Santa Anna at San Jacinto in April 1836. Texas became an independent republic and asked to join the United States.

Annexation was delayed for nearly a decade because Texas would be a large slave state and because it risked war with Mexico. After Polk won the 1844 election on an expansionist platform, Congress annexed Texas by joint resolution in 1845.

Thousands of families traveled the roughly 2,000-mile Oregon Trail from Missouri in the 1840s. Britain and the United States had shared the Oregon Country since 1818. Expansionists demanded all of it, but Polk, facing a war with Mexico, compromised: the Oregon Treaty of 1846 divided it at the 49th parallel.

Gold was found at Sutter's Mill in California in January 1848, and in 1849 a flood of 'forty-niners' arrived from the eastern United States, Latin America, Europe and China. California's non-Native population exploded, and it applied for statehood in 1849 (5.4). Chinese immigrants faced discriminatory taxes and violence.

For California's Native peoples, the Gold Rush was a catastrophe. Disease, starvation, enslavement and deliberate killings, some of them paid for by the state, reduced their population from about 150,000 in 1848 to about 30,000 by the early 1870s. On the Plains, migrants and their animals disrupted bison herds and grasslands, and the government began pushing Plains nations into treaties that limited their land.