I don't agree. The Southern states would have had an economy that was substantially the same had there been no slaves. Its climate and soil were well suited to producing valuable cash crops. Those crops were going to get produced given the demand for them. In addition to having an export/import based economy, the Southern states had a similar view of the constitution and the nature of the relationship between the states and the federal government. They were all Jeffersonian Democrats. That is, they believed in limited government and decentralized power and balanced budgets and very limited government spending. The ethos in the North was entirely different. They looked to a stronger federal government (which they could dominate) from the start.
“The Southern states would have had an economy that was substantially the same had there been no slaves. Its climate and soil were well suited to producing valuable cash crops. Those crops were going to get produced given the demand for them”
Have to disagree. In 1860 about 2 million slaves were directly involved with cotton agriculture. Without them, where would the 2 million white workers come from to replace the labor necessary to produce the 5.3 million bales of cotton that were produced that year. Without slaves, that would not have happened.
I should have been more specific. Slavery was the glue that held the Civil War together with respect to the South. Without it, they would have had a better case for secession. It would have also not given the North as great a reason; although not generally shared, to prosecute a war with the South upon secession.