The effective combination of business leadership, capital, technology, market, labor, and government support is especially noticeable in the development of the nation's first big business-- railroads. More than any other technological innovation or industrial achievement of the 19th century, the development of a nationwide railroad network has had the greatest impact on American economic life. Railroads create a market for goods that are national in scale, and encourage mass production, mass consumption, and economic specialization. The resources used in railroad-building promote the growth of other industries, especially coal and steel. Railroads also affect the routines of daily life. Soon after the American Railroad Association divided the country into four time zones, railroad time became standard time for all Americans. Finally, the most important innovations of the railroads are the creation of the modern stockholder corporation and the development of complex structures in finance, business management, and the regulation of competition. The building of dozens of separate local lines result in different distances between tracks and incompatible equipment. These inefficiencies minimized after the civil war through the alliance of competing railroads into combined trunk lines. A trunk line is the major route between large cities. Smaller branch lines connect trunk lines with outlying towns. The great age of railroad-building coincides with the settlement of the last frontier. In fact, railroads play a critical role in the trans-Mississippi West by promoting settlement on the Great Plains and linking the West with the East and thereby creating one great national market.