The Civil War (1861–1865) was fought over the question of slavery. The slave states wanted to perpetuate and spread slavery. The North sought to stop it from spreading into new territories. The North also had some abolitionists who wanted to destroy slavery, but they were in the minority. There were other differences between the North and South, too. The North had an industrial economy, while the South was agricultural. The North was more heavily populated and more urban than the South. The question of secession was important, too. The South maintained that states had the right to leave the Union, but the North argued that a state could not leave. The status of slavery was paramount, though.
The Founding Fathers were aware of the slavery issue when they created the United States in the late eighteenth century. Some wanted to abolish it, but concerns over slavery were secondary to the primary goal of creating a new, united nation.
The Compromise of 1820 was one of the earliest attempts to ameliorate the sectional divide. Because a balance of power was important in the Senate, Missouri entered the country as a slave state and Maine entered as a free state. Also, slavery was not allowed north of the southern border of Missouri.
After three decades, the Compromise of 1850 was passed in an attempt to end disputes over territory acquired from Mexico in 1848. But the decade before the Civil War was tense. There were arguments over the fate of escaped slaves. Southern fire-eaters urged the South to leave the Union. John Brown tried to lead a slave revolt in Virginia.
After Abraham Lincoln, the candidate of the anti-slavery Republican party, was elected president, the South seceded. War broke out in 1861, and the carnage lasted for four long years.