Slavery was a major issue that led to the Civil War. The Southern states were largely agricultural and relied on slave labor to work the plantations. The Northern states were more industrialized and did not rely on slavery. As the country expanded westward, the issue of whether new states would be allowed to enter the Union as slave states or free states became increasingly contentious.
2. The issue of states' rights
States' rights was another major issue that led to the Civil War. The Southern states believed that they had the right to make their own laws, even if those laws conflicted with federal laws. The Northern states believed that the federal government had the power to enforce its laws, even in the Southern states. The issue of states' rights came to a head with the passage of the Fugitive Slave Act of 1850, which required Northern states to return escaped slaves to their owners.