Slavery: The primary cause of the Civil War was the contentious issue of slavery. The Southern states, whose economy relied heavily on slave labor, sought to protect their right to own slaves, while the Northern states increasingly opposed the institution and advocated for its abolition.
States' Rights: The conflict between states' rights and federal authority also played a role in triggering the war. Southern states asserted their right to secede from the Union, while the federal government maintained that secession was illegal and sought to preserve the Union.