In the years before the Civil War, the economic interests of Americans in the North and Northwest grew increasingly further from those of Americans in the South and Southwest. The economies of many northern states had moved away from farming to industry. A lot of people in the North worked and lived in large cities like New York, Philadelphia, and Boston. The southern states, however, had maintained a large farming economy and this economy was based on slave labor. While the North no longer needed slaves, the South relied heavily upon slaves for their way of life.