After the American Revolution, a divide between the North and South began to widen. Industrialized northern states gradually passed laws freeing enslaved people, while southern states became increasingly committed to slavery. Many southerners came to view slavery as a linchpin of their agricultural economy, and as a justifiable social and political institution.

Throughout the first half of the 1800s, the nation struggled to manage the clash between these two incompatible viewpoints, working out deals such as the Missouri Compromise of 1820, which sought to balance the number of new free and slave states and drew a line through the nation’s western territories, with freedom to the north and slavery to the south. But in the last decade before war broke out, the conflict gained momentum and intensity. 

“Throughout the 1850s, a series of events increased sectionalism, emboldened southern secessionists, and deepened northern resolve to defend the Union and end slavery,” explains Jason Phillips, the Eberly Family Professor of Civil War Studies at West Virginia University, and author of the 2018 book Looming Civil War: How Nineteenth Century Americans Imagined the Future. “Many of these crises revolved around politics, but economic, social and cultural factors also contributed to the war’s origins.”

Here are nine events from the 1850s to the early 1860s that historians view as critical in the march toward the American Civil War.

The Compromise of 1850

In the wake of the Mexican War, tensions developed between the North and South over whether the western land gained by the U.S. should become free or slave territory. Things came to a head when California sought approval to enter the Union as a free state in 1849, which would have upset the balance struck by the Missouri Compromise several decades before. Senator Henry Clay, a Whig from Kentucky, proposed a package of legislation to resolve the disputes, but the Senate—after seven months of discussions—rejected his proposal.

Senator Stephen A. Douglas, a Democrat from Illinois, came up with an alternative proposal that admitted California, established Utah and New Mexico as territories that could decide for themselves whether to permit slavery, defined boundaries for the state of Texas, abolished the slave trade in the District of Columbia, and obligated the entire country to cooperate in the capture and return of escaped slaves. But the deal only postponed the conflict.

“They didn’t really compromise,” says Michael Green, an Associate Professor of History at the University of Nevada, Las Vegas and author of several books on the Civil War era, including Politics and America in Crisis: The Coming of the Civil War and Lincoln and the Election of 1860. “They just agreed to disagree.”

The Fugitive Slave Act

An existing federal law, enacted by Congress in 1793, allowed local governments to seize and return escaped slaves to their owners, and imposed penalties upon anyone who aided their flight. But the new version included in the Compromise of 1850 went much further, by compelling citizens to assist in capturing escapees, denying the captives the right to a jury trial, and increasing the penalty for anyone aiding their escape. It also put cases in the hands of federal commissioners who got $10 if a fugitive was returned, but only $5 if an alleged slave was determined to be a free Black.

Northern abolitionists rebelled against the law. After 50,000 anti-slavery protesters filled the streets of Boston to protest the arrest of a Black man named Anthony Burns in 1854, President Franklin Pierce sent federal troops to maintain order and provided a Navy ship to return Burns back to Virginia.

“Northerners who had questioned slavery said, ‘We told you so,’ and those who hadn’t thought to themselves, ‘This is going too far,’” says Green. “It’s a radicalizing moment.” As a result, Massachusetts and other free states began passing “personal liberty” laws, which made it difficult and costly for enslavers to prove their cases in court.

'Uncle Tom's Cabin' Is Published

Harriet Beecher Stowe, 1811-1896.
Library of Congress, Prints and Photographs Division
Harriet Beecher Stowe, 1811-1896.

In 1851, author Harriet Beecher Stowe, who was still grieving the loss of her 18-month-old son Samuel to cholera two years earlier, wrote to the publisher of a Washington, D.C.-based abolitionist newspaper, National Era, and offered to write a fictional serial about the cruelty of slavery. Stowe later explained that losing her child helped her to understand “what a poor slave mother may feel when her child is ripped away from her,” according to Stowe biographer Katie Griffiths.

Stowe’s story, published in 41 installments, boosted the paper’s circulation, and a Boston publisher decided to release it as a two-volume novel. Uncle Tom’s Cabin: Or, Life Among the Lowly sold 300,000 copies in its first year, and the vociferous public debate about the book exacerbated the differences between the North and South. Northerners were shocked by the brutal depiction of slavery, which Stowe had synthesized from published autobiographies of slaves and stories she had heard from friends and fugitive Blacks. In turn, “Southerners react noisily to it,” Green explains. “They’re saying, ‘This is terrible. You’re attacking us. You’re all against us.’” When Stowe visited the White House in 1862, President Lincoln asked, “So this is the little lady who made this big war?”

The Kansas-Nebraska Act

In 1854, Senator Douglas, the author of the Compromise of 1850, introduced another piece of legislation “to organize the Territory of Nebraska,” an area that covered not just that present-day state but also Kansas, as well as Montana and the Dakotas, according to the U.S. Senate’s history of the law. Douglas was promoting a transcontinental railroad that would pass through Chicago in his home state. But the envisioned northern route had to pass through the Nebraska territory, a place where slavery was prohibited by the 1820 Missouri Compromise. Rivals, including slave owners, wanted a southern route.

To get what he wanted, Douglas offered a compromise, which would allow settlers in those territories to decide whether to legalize slavery. Massachusetts Senator Charles Sumner, an opponent of slavery, attacked the proposal for creating “a dreary region of despotism.” Nevertheless it was passed by Congress, with cataclysmic results.

“It re-opened that land to the expansion of slavery, and destroyed a long-established political compromise on the issue of slavery in the West,” Phillips says. Pro-slavery and antislavery activists surged into the territories in an effort to sway the vote, and clashed violently in a conflict that became known as “Bleeding Kansas,” which foreshadowed the Civil War.

The Pottawatomie Massacre

A portrait of John Brown (May 9, 1800-December 2, 1859). Brown was an American abolitionist who advocated the use of armed insurrection to overthrow the institution of slavery in the United States.
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A portrait of John Brown (May 9, 1800-December 2, 1859).

One of those who went to Kansas was a radical abolitionist and religious zealot named John Brown, who had worked as a conductor on the Underground Railroad and founded an organization that helped slaves escape to Canada. Brown moved to Kansas Territory, where in May 1856, he was angered by the destruction of a newspaper office and other property in Lawrence, Kansas by pro-slavery forces. Brown decided retaliation was in order.

At a spot near a crossing on Pottawatomie Creek in Franklin, Kansas, Brown, four of his sons and several others lured five proslavery men out of their houses with a promise that they would not be harmed, and then slashed and stabbed them with a saber and shot them in the head, according to a contemporary account of the attack. Brown’s brutality was denounced by Southern newspapers and by some Northern ones as well, and it “aroused emotions and distrust on both sides,” as an article from the Kansas Historical Society notes. The fighting in Kansas continued for another two years.

The Dred Scott Decision

Dred Scott.
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Dred Scott sought his freedom after living with his family in free territory.

Dred Scott, an enslaved man, was born in Virginia and later lived in Alabama and Missouri. In 1831, his original enslaver died, and he was purchased by a U.S. Army surgeon named John Emerson. Emerson took him to the free state of Illinois and also Wisconsin, a territory where slavery was illegal due to the Missouri Compromise. During that time, Scott married and he and his wife had four children. In 1843, Emerson died, and several years after that, Scott and his wife sued Emerson’s widow in federal court for their freedom on the grounds that they had lived in free territory.

Scott, who was assisted financially by the family of his original owner, endured years of litigation until the case reached the U.S. Supreme Court. In an 1857 decision written by Chief Justice Roger Taney, the court decided that Scott was not entitled to U.S. citizenship and the protection of law, no matter where he had lived. In the court’s view, the Constitution’s framers had not intended for Black people to be free, but instead viewed them as property, with “no rights which the white man was bound to respect.” The ruling made further political compromise too difficult.

John Brown's Raid on Harper's Ferry

Illustration of abolitionist John Brown leading a raid on Confederate arsenal at Harper's Ferry, Virginia, 1859.
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Illustration of abolitionist John Brown leading a raid on a federal arsenal at Harper's Ferry, Virginia, 1859.

Brown dreamed of carrying out an even bigger attack, one that would ignite a mass uprising of Southern enslaved people. On a night in October 1859, he and a band of 22 men launched a raid on Harpers Ferry, a town in what is now West Virginia, and captured some prominent local citizens and seized the federal arsenal there. His small force soon was counterattacked by local militia, forcing him to seek refuge. The following afternoon, U.S. Marines under the command of then-Col. Robert E. Lee arrived and stormed the arsenal, killing many of Brown’s men and capturing him. Brown was tried and charged with treason, murder and slave insurrection, and sentenced to death. He was hanged in December 1859. While the attack failed to trigger the widespread revolt he envisioned, it drove the North and South even further apart.

“Northern abolitionists who preferred pacificism praised Brown as a martyr to the cause of freedom and even helped to finance his attack,” Phillips explains. “Southerners expected more acts of terrorism and prepared by bolstering their militias.” In many respects, Brown’s raid could be viewed as the first battle of the Civil War, he says.

The Election of 1860

Presidential candidate Abraham Lincoln debating his opponent Steven Douglas in front of a crowd, circa 1858.
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Presidential candidate Abraham Lincoln debating his opponent Steven Douglas in front of a crowd, circa 1858.

Abraham Lincoln, a self-taught lawyer who had served a single term in Congress, emerged in the mid-1850s as an articulate and persuasive critic of slavery, and achieved national prominence with a series of debates against Senator Stephen Douglas in an unsuccessful campaign for Douglas’s seat. When the Republican Party held a convention to nominate a presidential candidate, the chosen location of Chicago gave Lincoln a home-court advantage over more experienced politicians such as Senator William H. Seward of New York.

“When they set up the convention floor, they put Illinois in a spot where they could get to the other delegations that were less committed,” Green says. “The New York delegation, which was supporting Seward, was put in a corner where they couldn’t get out.” That made it difficult for them to negotiate and persuade others to support their candidate. In the general election, Lincoln caught more lucky breaks. After the Democrats were unable to decide upon a candidate, southern Democrats nominated John C. Breckenridge of Kentucky, while northerners nominated Douglas. Breckenridge and Constitutional Party Candidate John Bell split the South, while Lincoln swept the northeastern and midwestern states except for Missouri (which went to Douglas), as well as Oregon and California to win the presidency despite getting just 40 percent of the vote. “For the first time, the Electoral College worked against the South,” Green explains.

The Formation of the Confederacy

Jefferson Davis , the first and only President of the Confederate States of America, circa 1865
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Jefferson Davis , the first and only president of the Confederate States of America, circa 1865. 

The election of the first U.S. president who was a vocal opponent of slavery came as a shock to Southerners. “Now, there is going to be someone in the White House who is not going to do what the South says it wants done, reflexively,” Green explains. “Their feeling is, no matter what Lincoln says about protecting our rights, he’s not going to do that. We don’t trust him. He’s been elected by people who are out to get us.”

Less than six weeks after the election, the first secession convention met in Charleston South Carolina. About 60 percent of the 169 delegates were slave owners, and they voted unanimously to leave the Union. Local residents celebrated with bonfires, parades and the ringing of church bells. Five more states—Mississippi, Florida, Alabama, Georgia and Louisiana—soon followed. Representatives from those six states met in February 1861 to establish a unified government, which they called the Confederate States of America. Jefferson Davis of Mississippi was elected as Confederate President. Texas joined in March. 

After Confederate forces attacked Fort Sumter in April and Lincoln called for federal forces to retake it, four more states—Virginia, Arkansas, North Carolina and Tennessee—left the union and joined the Confederacy as well.

Though the Confederacy’s leaders didn’t realize it, they actually were hastening the end of what they sought to protect. “Had they stayed, slavery as an institution almost certainly would have survived much longer,” Green says.

Instead, a four-year, bloody war devastated much of the South, took the lives of more than 650,000 from both sides, and led to the emancipation of more than 3.9 million enslaved Black Americans, in addition to changing the nation in numerous other ways.

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