Final answer:
The Civil War was caused by the issue of slavery and the disagreement between the Northern and Southern states. The Southern states seceded from the Union to form the Confederacy, leading to the war to preserve the United States.
Step-by-step explanation:
The Civil War was primarily caused by the issue of slavery. The Southern states believed in the right to own slaves, while the Northern states opposed it. This disagreement over slavery led to the secession of Southern states from the Union and the formation of the Confederate States of America. The war then ensued as a result of the Confederacy's desire to maintain slavery and the Union's aim to preserve the United States as a whole.
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