By Keli Holt
In April 1861, the United States was torn apart by a devastating internal conflict—the Civil War. This war began just 78 years after the original 13 colonies along the Atlantic seaboard had gained independence from Britain. Despite decades of unity, growing differences between the North and South—especially over the issue of slavery—led many in the South to believe they could no longer be part of the same nation. Several Southern states chose to break away and form a new country called the Confederate States of America, or the Confederacy. While their constitution closely resembled the U.S. Constitution, it included one major difference: it clearly protected the institution of slavery.
Background
In 1783, when the United States gained independence, slavery was legal throughout the country. Many of the Founding Fathers—leaders who fought the Revolutionary War and helped write the U.S. Constitution—acknowledged the contradiction of building a nation based on liberty while enslaving millions of African people. Some hoped that slavery would gradually come to an end, both for moral reasons and because it was not economically viable everywhere.
In the North, slavery became less common after independence. Cold winters and rocky soil made large-scale farming difficult, so most Northern families ran small farms without relying on enslaved labor. People in the North turned to other industries like fishing, shipbuilding, and international trade. Over time, Northern states passed laws to abolish slavery.
In contrast, the Southern economy was built on plantation agriculture, which depended heavily on enslaved labor. The South’s climate and fertile soil were ideal for growing labor-intensive crops such as cotton, tobacco, and rice. As the North industrialized, the South remained mostly agricultural, and many wealthy white Southerners resisted ending slavery, which was the foundation of their economic and social system. When the U.S. Constitution was written in 1787, slavery was allowed to continue as part of a compromise between Northern and Southern leaders.
As the country expanded westward in the 1800s, debates erupted over whether slavery should be allowed in new territories. Southern leaders argued that enslaved people were their property and that they had a right to bring them wherever they went. Many Northerners strongly opposed the spread of slavery, both because they believed it was morally wrong and because they feared it would give slaveholding states more political power.
One early attempt to limit slavery’s expansion was the Northwest Ordinance of 1787, which banned slavery in the newly formed territories that would later become Ohio, Indiana, and Illinois. Because most people moving into those areas were from the North and didn’t rely on enslaved labor, this didn’t initially spark major conflict.
But in 1804, when President Thomas Jefferson purchased the vast Louisiana Territory from France, questions about slavery in new western lands reemerged. The Missouri Compromise of 1820 tried to solve the issue by allowing Missouri to join as a slave state and Maine as a free state, while also drawing a line across the country: states north of the line would be free, and those south of it could allow slavery.
That peace didn’t last. After the Mexican-American War ended in 1848, the U.S. gained a huge amount of land in the Southwest. Much of this land lay south of the Missouri Compromise line, and Southern leaders wanted slavery to be allowed there. Many Northerners were alarmed, fearing that the balance of power would tip in favor of slaveholding states.
To avoid a national crisis, Congress passed the Compromise of 1850. It admitted California as a free state, and gave people in the territories of New Mexico and Utah the right to vote on whether to allow slavery. To gain Southern support, the Compromise included the Fugitive Slave Act, which required officials in free states to capture and return people who had escaped slavery. This law outraged many Northerners, who believed it forced them to take part in a system they found deeply unjust.
In 1854, the Kansas-Nebraska Act allowed settlers in those territories—both north of the Missouri Compromise line—to decide the slavery question by popular vote. This act overturned previous agreements and led to violence as people from both sides flooded into Kansas to influence the vote. The region became known as “Bleeding Kansas” due to the deadly clashes between pro- and anti-slavery groups.
By the late 1850s, the fragile peace between free and slaveholding states had broken down completely. Southern leaders feared that the North, with its growing population and economy, would soon pass laws to abolish slavery nationwide. Northern leaders feared the spread of slavery into new territories and the growing power of slaveholding interests in the government.
When Abraham Lincoln was elected president in 1860, many in the South saw his victory as a direct threat to their way of life—even though he had promised not to interfere with slavery where it already existed. Before Lincoln even took office, several Southern states seceded from the Union and formed the Confederacy. The Civil War had begun. It would take four painful years and over 600,000 lives to reunite the country—and to bring slavery in the United States to an end.
