The close relationship between railroad expansion and the general development and prosperity of the country is nowhere brought more distinctly into relief than in connection with the construction of the Pacific railroads. With the opening of a transcontinental line the vast El Dorado of the West was laid practically at the doorstep of Eastern capital. Not only did American pioneers turn definitely toward the West, but foreign emigrants bent their steps in vast numbers in that direction, and capital in steadily increasing amounts made its way there. Towns sprang up everywhere and soon developed into busy centers of trade and commerce. Caravan trains, which a few years before had followed a single westward line, now started from points along the railroad artery and penetrated far to the north and south. The settlers knew that the time was not far distant when all the vast territory west of the Missouri, from the Canadian border to the Rio Grande, would be reached by the rapid spread of the railroad. In the sixties and seventies there sprang up and rapidly developed in size and importance such centers as Kansas City, Sioux City, Denver, Salt Lake City, Cheyenne, Atchison, Topeka, Helena, Portland, Seattle, Duluth, St. Paul, Minneapolis, and scores of smaller places. The entire Pacific slope was soon dotted with towns and cities, and even the great arid plains of the West--as well as the "Great American Desert" covering Utah, Arizona, New Mexico, and parts of Nevada--began to take on signs of life which had not been dreamed of a decade before. But the development of this great section of the country during the next few years was even more notable. By 1880 four different lines of railroad were running through to the Pacific States, and a fifth, the Denver and Rio Grande, had penetrated through the mountains of Colorado and across Utah to the Great Salt Lake. These were the years when the modern industrial era was really beginning. Man's viewpoint was changing, and instead of remaining content with the material achievements of the Atlantic and Central sections of the continent, he began to realize that the vast Western regions and the thousand miles of Pacific coast line were destined to be America's inexhaustible patrimony for the years to come.