This detailed study of Henry Clay and the American System—a program of vigorous economic nationalism dependent on active government and constitutional aspects of what was perhaps Clay’s greatest contribution to national policy, a contribution that has received surprisingly little study until now. During the first half of the nineteenth century the new United States experienced rapid material growth, transforming a largely agrarian, pre-modern economy into a diversified, industrializing one. As Speaker of the House in the years following the War of 1812, and later as founder of the Whig party, Clay argued strongly for the development of a home market for domestic goods so that Americans would not be dependent on foreign imports. This “Americ...