Causes of the American Civil War

How did the Missouri Compromise attempt to address the spread of slavery, and why did it increase sectional tension?

It admitted Missouri as a slave state and Maine as a free state to maintain Senate balance, and banned slavery north of the 36°30′ line in the Louisiana Territory. While it temporarily reduced conflict, it highlighted the growing divide between North and South and introduced slavery as a permanent national political issue.

How did James K. Polk’s campaign platform reflect the expansionist desires of the U.S.?

Polk ran on a platform of Manifest Destiny, promising the annexation of Texas, acquisition of the Oregon Territory, and expansion to California. His victory accelerated territorial expansion but intensified debates over whether new states would permit slavery.

Why was the annexation of Texas controversial?

Texas entered as a slave state, upsetting the balance of free and slave states and angering Mexico, which still claimed Texas. Northerners feared it was part of a “Slave Power” conspiracy to expand slavery’s political influence.

What were the consequences of the Treaty of Guadalupe Hidalgo for the U.S.?

It ended the Mexican-American War and granted the U.S. the Mexican Cession (California, Nevada, Utah, Arizona, New Mexico, etc.) in exchange for 15 million. This reopened the slavery expansion debate and led to sectional conflict over new territories.

What did the Wilmot Proviso propose, and why was it significant?

It proposed banning slavery in any territory gained from Mexico. Although it failed, it intensified sectional divisions and led to political realignment as northern and southern politicians split along regional rather than party lines.

What did the Compromise of 1850 include, and why did it fail to prevent conflict?

It admitted California as a free state, allowed popular sovereignty in Utah and New Mexico, banned the slave trade in Washington D.C., and passed a stricter Fugitive Slave Act. The South gained stronger slave-catching powers, which angered the North and increased abolitionist resistance.

What was the purpose of the Gadsden Purchase?

The U.S. bought land from Mexico (southern Arizona and New Mexico) for 10 million to build a southern transcontinental railroad. It contributed to debates over expanding slavery and highlighted sectional economic differences.

Why was the Republican Party formed, and what did it stand for?

Formed in response to the Kansas-Nebraska Act, the party united anti-slavery Whigs, Democrats, and Free-Soilers. It opposed the expansion of slavery into western territories and promoted free labor.

What was the Free-Soil ideology?

It argued that slavery should not expand westward because it limited opportunities for free white labor. It was not purely moral; it was based on economic competition and fear of slave power.

Why is James Buchanan blamed for the growing crisis before the Civil War?

He believed the Constitution did not allow him to stop secession and refused to act against southern aggression. His failure to address slavery or secession helped push the nation closer to war.

Why was Uncle Tom’s Cabin significant in the slavery debate?

Harriet Beecher Stowe’s novel portrayed the brutal reality of slavery, increasing abolitionist support in the North and angering the South, which accused it of exaggeration and propaganda.

What was the Underground Railroad, and why did the South oppose it?

A secret network of abolitionists who helped enslaved people escape to free states or Canada. Southerners saw it as a violation of property rights, especially after the Fugitive Slave Act of 1850.

What was debated in the Lincoln-Douglas debates, and why were they important?

Abraham Lincoln and Stephen Douglas debated slavery in the territories. Lincoln opposed expansion but not immediate abolition; Douglas promoted popular sovereignty. The debates made Lincoln nationally famous.

What happened at Pottawatomie Creek, and why was it important?

In retaliation for pro-slavery violence, abolitionist John Brown killed five pro-slavery settlers in Kansas. It escalated violence in “Bleeding Kansas” and deepened sectional hatred.

Why is Kansas referred to as "Bleeding Kansas"?

After the Kansas-Nebraska Act allowed popular sovereignty, pro- and anti-slavery settlers flooded Kansas, leading to violent clashes. It showed that popular sovereignty did not resolve the slavery issue.

What did the Kansas-Nebraska Act do, and why was it controversial?

It allowed Kansas and Nebraska to decide slavery by popular sovereignty and repealed the Missouri Compromise line. It angered the North, led to Bleeding Kansas, and helped create the Republican Party.

What was the Ostend Manifesto, and why did it anger the North?

A secret document suggesting the U.S. buy Cuba from Spain, or seize it by force, to expand slavery. Northerners saw it as proof of a “Slave Power” conspiracy.

What was the Supreme Court’s ruling in Dred Scott, and why was it significant?

The Court ruled enslaved people were property, not citizens, and Congress had no right to ban slavery in territories. It nullified the Missouri Compromise and enraged the North.

What happened in the Sumner-Brooks incident, and what did it symbolize?

After anti-slavery senator Charles Sumner insulted pro-slavery politicians, Congressman Preston Brooks beat him with a cane on the Senate floor. It showed that politics had become violent and deeply polarized.

What caused the Panic of 1857, and how did it affect sectional tensions?

A financial crisis caused by falling grain prices and failed banks. The North was hit harder than the South, reinforcing southern belief in the superiority of their cotton-based economy.

What were John Brown's goals at Harpers Ferry?

He tried to seize a federal arsenal in Virginia to start a slave uprising. He failed and was executed, but became a martyr in the North and a terrorist in the South.

Why did Lincoln’s election lead directly to secession?

Lincoln won without any southern electoral votes and opposed the expansion of slavery. Southerners believed they had lost political power, so South Carolina and others seceded.

What was secession, and why did southern states justify it?

Secession was the withdrawal of 11 southern states from the Union to form the Confederate States of America. They claimed states’ rights and protection of slavery as constitutional justifications.