The commerce of Lake Superior could not await the building of a canal around the foaming rapids of the St. Mary's River, its one outlet to the lower lakes. In the decade following the discovery of copper and iron more than a dozen ships, one even of as much as five hundred tons, were hauled bodily across the portage between Lake Huron and Lake Superior. The last link of navigation in the Great Lake system, however, was made possible in 1852 by a grant by Congress of 750,000 acres of Michigan land. Although only a mile in length, the work proved to be of unusual difficulty since the pathway for the canal had to be blasted throughout practically its whole length out of solid rock. It was completed in 1855, and the princely empire "in the moon" was in a position to make its terms with the coal fields of Pennsylvania and to usher in the iron age of transportation and construction. It is only in the light of this awakening of the lands around the Great Lakes that one can see plainly the task which fell to the lot of the successors of the frail Walk-in-the-Water and sturdier Superior of the early twenties. For the first fifteen years the steamboat found its mission in carrying the thousands of emigrants pouring into the Northwest, a heterogeneous multitude which made the Lake Erie boats seem, to one traveler at least, filled with "men, women and children, beds, cradles, kettles, and frying pans." These craft were built after the pattern of the Walk-in-the-Water--side-wheelers with a steering wheel at the stern. No cabins or staterooms on deck were provided; and amid such freight as the thriving young towns provided were to be found the twenty or thirty cords of wood which the engines required as fuel. The second period of steamboating began with the opening of the Ohio Canal and the Welland Canal about 1834 and extended another fifteen years to the middle of the century, when it underwent a transformation owing to the great development of Chicago, the completion of the Illinois and Michigan and St. Mary's canals, and the new railways. This second period was marked by the building of such steamers as the Michigan, the Great Western, and the Illinois. These were the first boats with an upper cabin and were looked upon with marked suspicion by those best acquainted with the severe storms upon the Great Lakes. The Michigan, of 475 tons, built by Oliver Newberry at Detroit in 1833, is said to have been the first ship of this type. These boats proved their seaworthiness and caused a revolution in the construction of lake craft. Later in this period freight transportation saw an equally radical advance with the building of the first propellers. The sloop-rigged Vandalia, built by Sylvester Doolittle at Oswego on Lake Ontario in 1841-42, was the first of the propeller type and was soon followed by the Hercules, the Samson, and the Detroit.