a1 Assistant Professor, Department of Economics, Washington University, Campus Box 1208. St. Louis, MO 63130–4899, and Faculty Research Fellow, NBER.
Between the nineteenth and twentieth centureis, the regions of the United States went from a set of relatively isolated regional economies to an integrated national economy. Economic integration, as we as long-run secular changes in the economic structure associated with economic growth, played an important role in determining U.S. regional industrial structures. Moreover, although differences in regional industrial structures do not explain all the variations in regional income per capita, they played an important role in causing U.S. regional incomes to diverge and converge between the nineteenth and twentieth centuries.