Thomas was once a professor at the University of Georgia. His original work is called The Confederacy as a Revolutionary Experience. He then expanded on that original thesis with his book The Confederate Nation.
Thomas shows that the south had an expanding middle class of merchants. It just wasn't rich planters, poor whites, and slaves. The south experienced a dramatic increase in industry during the war and they showed a remarkable degree of flexibility in being able to switch from cotton to corn production.
____________________ "Cleburne is here!" meant that all was well. -Daniel Harvey Hill