For a time the most popular of these projects was the old fur trade route of the Wisconsin and Fox rivers. A canal was dug along the famous carrying trail at Portage, and the federal government was induced to deepen Fox River, which is naturally very shallow, and to attempt to create a permanent channel in the Wisconsin River. But, although much money has been spent on these schemes, from that day to this, the Fox-Wisconsin route is still impracticable save to boats of exceptionally light draft; and in our time the project of connecting the Mississippi River with Lake Michigan, by the way of Portage and Green Bay, is almost wholly abandoned. Another scheme was the proposed Milwaukee and Rock River canal, by which Milwaukee was to be connected with the Rock River, which joins the Mississippi at Rock Island; but this plan died a still earlier death. It was the struggle to connect the port of Milwaukee with the lead region that finally led to the building of the railroad between that city and Prairie du Chien. More immediately effective for the benefit of the lead trade, was the opening of a wagon road from the lead mining towns, through Madison, to Milwaukee, along which great canvas-covered caravans of ore-laden "prairie schooners" toiled slowly from the mines to the Lake Michigan docks, a distance of about a hundred and fifty miles. Other roads led to Galena and Prairie du Chien, where the Mississippi River boats awaited similar fleets of "schooners" from the interior. A good deal of the lead was sent by similar conveyances to Helena, a little village on the Wisconsin River, where a shot tower had been built against the face of a high cliff; from here, shallow-draft boats took the shot to Green Bay, by way of the Portage Canal and Fox River, or descended the Wisconsin to Prairie du Chien. From various causes, the lead trade of the Upper Mississippi region had sadly declined by 1857. Among these causes was the finding of gold in California (1849), which attracted large numbers of the miners to a more profitable field; again, the surface or shallow diggings having been exhausted, much more capital was required to operate in the lower levels; more serious was the lack of sufficient transportation facilities, and these did not come until the great silver mines of the Rocky Mountains had been opened, lead being thenceforth more profitably produced in connection with silver. The effect of the lead industry upon the development of Wisconsin was important. Many years before farmers would naturally have sought southern Wisconsin in their pushing westward for fresh lands, the opening of the mines brought thither a large and energetic industrial population, and a considerable capital, and awakened popular interest in land and water transportation routes. THE WINNEBAGO WAR