"Developments in transportation, rather than in manufacturing and agriculture, sparked American economic growth in the first half of the nineteenth century." is not accurate. While development in transportation played a fundamental role in America's growth, if it were not for developments in manufacturing and agriculture the new technology in transportation could not have successfully been completed. Without the raw materials, and the products which came out of the early US iron and steel industry, (which were all ultimately determined by the United States agricultural market), the transportation revolution could not have been carried out. …
