How did the social classes in the north and south differ? Why?

There were indeed stark social differences between the North and the South in the years leading up to the American Civil War ... There were also nearly four million slaves in the South by 1860. These people lived entirely separate from the rest of southern society and had none of the rights of citizens. They differed because 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 clash brought on the war.