With the close of the war political power passed for many years to the northern half of the Mississippi Valley, as the names of Grant, Hayes, Garfield, Harrison, and McKinley indicate. The population of the Valley grew from about fifteen millions in 1860 to over forty millions in 1900--over half the total population of the United States. The significance of its industrial growth is not likely to be overestimated or overlooked. On its northern border, from near Minnesota's boundary line, through the Great Lakes to Pittsburgh, on its eastern edge, runs a huge movement of iron from mine to factory. This industry is basal in American life, and it has revolutionized the industry of the world. The United States produces pig iron and steel in amount equal to her two greatest competitors combined, and the iron ores for this product are chiefly in the Mississippi Valley. It is the chief producer of coal, thereby enabling the United States almost to equal the combined production of Germany and Great Britain; and great oil fields of the nation are in its midst. Its huge crops of wheat and corn and its cattle are the main resources for the United States and are drawn upon by Europe. Its cotton furnishes two-thirds of the world's factory supply. Its railroad system constitutes the greatest transportation network in the world. Again it is seeking industrial consolidation by demanding improvement of its vast water system as a unit. If this design, favored by Roosevelt, shall at some time be accomplished, again the bulk of the commerce of the Valley may flow along the old routes to New Orleans; and to Galveston by the development of southern railroad outlets after the building of the Panama Canal. For the development and exploitation of these and of the transportation and trade interests of the Middle West, Eastern capital has been consolidated into huge corporations, trusts, and combinations. With the influx of capital, and the rise of cities and manufactures, portions of the Mississippi Valley have become assimilated with the East. With the end of the era of free lands the basis of its democratic society is passing away.