The decade of the forties was also the period of Iowa's rapid increase. Although not politically a part of the Old Northwest, in history she is closely related to that region. Her growth was by no means so rapid as was Wisconsin's, for the proportion of foreign immigration was less. Whereas in 1850 more than one-third of Wisconsin's population was foreign-born, the proportion for Iowa was not much over one-tenth. The main body of her people finally came from the Middle States, and Illinois and Ohio; but Southern elements were well represented, particularly among her political leaders. The middle of the century was the turning-point in the transfer of control in the Northwest. Below the line of the old national turnpike, marked by the cities of Columbus, Indianapolis, Vandalia, and St. Louis, the counties had acquired a stability of settlement; and partly because of the Southern element, partly because of a natural tendency of new communities toward Jacksonian ideals, these counties were preponderantly Democratic. But the Southern migration had turned to the cotton areas of the Southwest, and the development of railroads and canals had broken the historic commercial ascendancy of the Mississippi River; New Orleans was yielding the scepter to New York. The tide of migration from the North poured along these newly opened channels, and occupied the less settled counties above the national turnpike. In cities like Columbus and Indianapolis, where the two currents had run side by side, the combined elements were most clearly marked, but in the Northwest as a whole a varied population had been formed. This region seemed to represent and understand the various parts of the Union. It was this aspect which Mr. Vinton, of Ohio, urged in Congress when he made his notable speech in favor of the admission of Iowa. He pleaded the mission of the Northwest as the mediator between the sections and the unifying agency in the nation, with such power and pathos as to thrill even John Quincy Adams.