"On the eve of the Civil War the United States had already achieved rapid and sustained economic expansion. We had filled out our territorial boundaries, and the frontier was already encroaching upon the parched lands in the lee of the Rocky Mountains and moving east of the Sierra Nevadas. We were an industrial nation second only to Britain in manufacturing. Our expansion had been matched by an acceleration of economic well-being. The obstacles to American economic growth had been removed before the Civil War took place. That war was a costly and bitter interruption." Integrating economic...