The rise of the United States as a world power in the twentieth century was based on the reation of a specialized regional structure in the nineteenth century. Four major elements helped evolve America¡s nineteenth century regional structure from the agriculture based, post-independence country that it was, into the twentieth century world power it would become. The four main elements are: 1. Improvements in transportation, specifically the development of the railroad system, 2. Growing regional economic and industrial specialization, 3. A shift from an agricultural to an industry-based economy, 4. Economic expansion overseas. The effect of these elements in some cases was direct and in others was more indirect. Transportation did not directly lead to America becoming a world power but it did provide the infrastructure for some of the later elements. A more direct affect resulted from increased regional specialization as well as industrialization. The final point, overseas expansion had the most direct link to America¡s transformation into a world power.
             During the first half of the nineteenth century improvements in transportation occurred rapidly. Roads, steamboats, canals, and railroads all had a positive impact on the American economy, most notably the development of the railroad.
             ¡§The Railroad has a justly deserved place as the pivotal integrator of the national space-economy between 1860 and 1920 and as a major component of the late 19th-century economic growth. ¡§(David .R Meyer, p.323)
             The railroad fostered a more diverse and competitive America by introducing new markets into each region and allowing the acquisition of different or simply cheaper goods from other regions. The result was a broad-based yet competitive country-wide trading region with lowered costs for the entire economy. Even the process of building the railroad helped stimulate specific industries like the copper, steel and iron industri...