Expansion and the slavery question
Westward expansion added huge territories. Each new territory reopened the explosive question of whether slavery would spread.
Manifest Destiny
Manifest Destiny was the belief, popular in the 1840s, that the United States was destined to expand across North America. It justified the annexation of Texas (1845), the division of the Oregon Country with Britain (1846), and war with Mexico. It ignored or dismissed the rights of Native peoples and Mexicans living there.
The Mexican-American War
The US went to war with Mexico in 1846 after disputes over the Texas border. The 1848 Treaty of Guadalupe Hidalgo gave the US about half of Mexico's territory, including California and much of the Southwest. Critics, including a young congressman named Abraham Lincoln, questioned the war's justification.
The Wilmot Proviso and sectional tension
The Wilmot Proviso (1846) proposed banning slavery in all land gained from Mexico. It passed the House repeatedly but failed in the Senate, and it revealed a deep split along sectional lines rather than party lines. The question of slavery in the territories now dominated politics.
The Compromise of 1850
The Compromise of 1850 admitted California as a free state, let the territories of New Mexico and Utah decide on slavery by popular sovereignty, banned the slave trade (but not slavery) in Washington, D.C., and passed a strict Fugitive Slave Act, which required Northerners to help return people who escaped slavery and outraged many.
Uncle Tom's Cabin and abolitionism
Harriet Beecher Stowe's novel Uncle Tom's Cabin (1852) sold hundreds of thousands of copies and turned many Northerners against slavery. Abolitionists such as Frederick Douglass, who had escaped slavery, and William Lloyd Garrison campaigned for immediate emancipation. Harriet Tubman guided enslaved people to freedom on the Underground Railroad.
The Kansas-Nebraska Act and Bleeding Kansas
The Kansas-Nebraska Act (1854), promoted by Stephen Douglas, let settlers in those territories decide on slavery by popular sovereignty, effectively repealing the Missouri Compromise line. Pro- and anti-slavery settlers rushed into Kansas, and violence erupted: 'Bleeding Kansas'. The act also led to the founding of the Republican Party, opposed to slavery's expansion.
Dred Scott v. Sandford
In Dred Scott v. Sandford (1857), the Supreme Court ruled that Black Americans, free or enslaved, were not citizens and could not sue in federal court, and that Congress could not ban slavery in the territories. The decision delighted many Southerners and enraged Northerners, deepening the crisis.
Lincoln and the road to secession
Abraham Lincoln gained national attention in the 1858 Lincoln-Douglas debates. In 1859, John Brown's raid on Harpers Ferry, aiming to start a slave uprising, terrified Southerners. When Lincoln, a Republican opposed to slavery's expansion, won the 1860 election without carrying a single Southern state, South Carolina seceded, followed by other Deep South states.
Key takeaways
Manifest Destiny drove expansion; the Mexican-American War added vast territory. The Wilmot Proviso exposed sectional division. The Compromise of 1850 included a harsh Fugitive Slave Act. Uncle Tom's Cabin and abolitionists such as Douglass and Tubman fuelled antislavery feeling. The Kansas-Nebraska Act led to Bleeding Kansas and the Republican Party. Dred Scott (1857) denied Black citizenship. Lincoln's 1860 election triggered secession.
Flashcard
Belief in destined continental expansion
Check your understanding
Why did the Kansas-Nebraska Act (1854) increase tensions?