The document summarizes the impact of railroads and technological innovations after Reconstruction in 3 points: 1) Railroads increased demand for steel by using steel rails and transporting resources like iron and coal needed to produce steel. Railroads also vertically integrated the steel industry. 2) The transcontinental railroad connected the east and west coasts, opening the western U.S. to settlement. It was built in part by Chinese laborers and spurred growth through increased markets and materials transportation. 3) John D. Rockefeller formed the Standard Oil monopoly by buying competitors and forming a trust to control 90% of U.S. oil refineries. The company was broken up in 1911 for being a monopoly.