US history: the Civil War and Reconstruction (grade 11)
The fight over whether slavery would spread west split the nation. The Civil War ended slavery, and Reconstruction tested what freedom would mean.
The fight over slavery's spread
💡 Each new state could tip the balance of power in Congress, so the spread of slavery into the West drove the nation toward war.
Each state gets two senators. So every new western state could shift the balance between free and slave states in the Senate. The Missouri Compromise of 1820 drew a line to divide the West. The Compromise of 1850 tried again, and it included the Fugitive Slave Act. That law let people who escaped slavery be captured even in free Northern states and returned. Many freedom seekers on the Underground Railroad, a secret network of helpers and safe houses, went all the way to Canada, where slavery was illegal.
The Kansas-Nebraska Act of 1854 let settlers in those territories vote on slavery. Settlers for and against slavery rushed into Kansas, and violence broke out. Northern anger grew, and the new antislavery Republican Party gained strength.
In Dred Scott v. Sandford (1857), the Supreme Court ruled that Black Americans were not citizens and that Congress could not ban slavery in the territories. Lines like the Missouri Compromise could no longer keep slavery out of the West. In 1858, Lincoln warned that 'a house divided against itself cannot stand,' meaning the nation could not stay half slave and half free. John Brown's raid on Harpers Ferry followed in 1859.
For each event, ask whether it made slavery's spread easier or harder, and who would be angry. When a ruling takes away the main tool one side used for compromise, the conflict gets harder to settle peacefully.
- territory
- land owned by the US that was not yet a state
- Fugitive Slave Act
- an 1850 law requiring escaped enslaved people to be returned