Final answer:
The problem that led to the Civil War was slavery.
Step-by-step explanation:
The problem that led to the Civil War was slavery. Slavery was a major factor in the tensions between the Northern and Southern states, as the North wanted to abolish slavery while the South wanted to maintain it. The issue of slavery became increasingly divisive, leading to political unrest, the formation of anti-slavery movements, and the eventual outbreak of the Civil War.
Learn more about Causes of the Civil War