The fur trade was at its height in 1820 and was seriously on the wane by 1835; the lumber industry was of a size to be reckoned with by 1830; in the next decade, between 1840 and 1850, the mineral industry came into existence. The earliest explorers had known of the presence in the Lake Superior region of large deposits of virgin copper. References are made to these deposits in the Jesuit “Relations.” The first attempt at mining was made in 1770 by Alexander Henry, the trader at Mackinac, after the Indian wars were over, but he was not successful. With the coming of the Americans, copper mining began in earnest. Indeed, it was said by a friend, who told the story twenty years after the conversation, that Benjamin Franklin told him that when he was drawing the treaty of peace in Paris he had access to the journals and charts of a corps of French engineers who had been exploring Lake Superior, and that he drew the line through Lake Superior to include the best and largest supply of copper in the American possessions. “The time will come,” said Franklin, “when drawing that line will be considered the greatest service I ever rendered my country.” Copper and silver were the minerals whose discovery created the most enthusiasm, and several companies were formed for their mining in the thirties and forties after the expedition of Governor Cass. Of these at the time of the Civil War only two were paying dividends. In 1865 the Calumet and Hecla mines were started and began to develop that part of the rich upper peninsula of Michigan known as Keweenaw Point. From that time the mines have sent out yearly thousands of tons, and millions of dollars are realized every year from them. Until 1880, when copper was found in Montana and Arizona, Michigan was the only source of supply in the United States, and sent out five-sixths of the nation’s whole product. Since that time her output has trebled, but owing to the great increase of mining in the West this tremendous tonnage of copper is to-day only one-fourth of the total, although still a most important factor in the contribution of the lake region to the wealth of the country. [Illustration: An Early Lake Superior Copper Mine]