Final answer:
The American Civil War was caused by the issue of slavery and the differences in economic and social systems between the North and the South.
Step-by-step explanation:
The Cause of the American Civil War 1861-1865
The American Civil War was primarily caused by the issue of slavery. The conflict between the Northern states, which were industrialized and embraced abolitionism, and the Southern states, which heavily relied on slave labor and fought to protect their economic and social system, was at the core of the war.
Another key factor was the debate over states' rights, with the Southern states believing they had the right to secede from the Union. The election of Abraham Lincoln as the President of the United States in 1860 further heightened tensions, leading to the secession of Southern states and the eventual outbreak of war.
The primary cause of the American Civil War, however, remains the institution of slavery and the fundamental differences in the economic and social systems between the North and the South.
Learn more about the cause of the American Civil War