Beginning with 1839, the emigrant travel to Chicago was so great that a line of eight vessels engaged in this traffic alone, each vessel making the trip once in sixteen days. It was now impossible to build ships fast enough to keep pace with the developing commerce. During the ten years between 1830 and 1840, the population of Michigan increased from 31,000 to 212,000, and practically the whole of it came by lake. In 1840, Wisconsin’s population was less than 31,000; ten years later, it was 305,000. By 1846, the value of the commerce of the Lakes was already enormous. Its value for that year is estimated to have been over eighty millions of dollars. In 1835, the American Fur Company built the _John Jacob Astor_, the first large ship to sail Lake Superior, and the trade in copper began soon after. With the discovery of the rich mineral deposits, hundreds of prospectors began flocking into the North, men with capital hurried to the regions of the red metal, and, in the race after wealth, vessel-men did not wait to build ships on Superior but hauled their vessels bodily across the mile portage at Sault Ste. Marie. In 1855 was built the Falls Canal, and from that date, the commerce of Superior became an important factor in the traffic of the Lakes. All that was needed to make it the most important body of fresh water on the globe was the discovery of iron. This discovery, and the part that iron has played in the making of our nation, have been described in preceding pages. [Illustration: Map of the Great Lakes Region] INDEX A Aborigines, warlike, of the early history of the Lakes, 163 Adams, Mayor, of Buffalo, 127 Aillon, Father Joseph de la Roche d’, mission formed by, 168 Algonquin, a tribe of Indians, 164 _Alpena_, the, of Lake Michigan, 102 American Fur Company, the, 220 American Shipbuilding Company, the, 15, 16 Argosy, the huge, of the Lakes, 26 _Ariel_, the battle-ship, 217 Assiniboines, the, of Minnesota, 176 Astor, John Jacob, 220 _Atlanta_, the loss of the, 102 _Atlantic_, loss of, with valuable cargo, 110 B _Bannockburn_, the mystery of the, 103 Barre, Governor De la, of Canada, 177 Beauharnois, Governor, of Canada, 1727, 180 Beaver Island, 88 Belle Isle, a great pleasure ground, 85 _B. F. Jones_, the cargo of, 60 “Bread Basket of the World,” the future, 60 Brock, General, the death of, 84 Brule, Stephen, discovers Lake Superior, 166 Buffalo, shipyards at, 10 Burnett, Governor, of New York, 180 C Cabins on a freighter, 138 Calbick, James A., President of the Lumber Carriers’ Association, 51 _Caledonia_, the capture of, 198 Canada, the fertile regions of western, 63 Canadian Niagara Falls Company, the, 133 Canals, the, at Sault Ste. Marie, 27 Cargoes of the Great Lakes, 1 Caron, Joseph Le, discovers Lake Ontario, 166 “Carriers,” the, of the Great Lakes, 24 Cayuga Indians, the, 165 Cheapness of travel on the Lakes, 75