For years, textbook authors have contended that economic difference between North and South was the primary cause of the Civil War. The northern economy relied on manufacturing and the agricultural southern economy depended on the production of cotton. The desire of southerners for unpaid workers to pick the valuable cotton strengthened their need for slavery. The industrial revolution in the North did not require slave labor and so people there opposed it. The clash brought on the war.
Economic divergence is certainly one of the reasons for the Civil War, but neither the major one nor the only one. Many factors brought about the war. Focusing only on different economies would be like arguing that one professional football team will always win because it has taller players.
The true causes of the Civil War are downright intriguing and just as complex as the conflict itself.