Iron Ore and Lake Superior
The history of the other major natural resource input -- iron ore has, however, received much less attention. Yet the iron mines of Lake Superior were of central importance to the evolution of America's iron and steel industry. They first become an important supplier of ore in the 1860s. Their importance steadily increased as the nation's industrial revolution accelerated in the aftermath of the Civil War, and by 1890 Lake Superior mines produced over half of the nation's iron ore. By 1900 that figure had reached two thirds, and for most of the twentieth century Lake Superior iron mines provided three-quarters to four-fifths of all iron ores produced in the United States. Today these mines are the only producers of American iron ore.
Despite the importance of iron ore to the iron and steel industry, and hence to American industrialization, documentary records dealing with iron mining are relatively scarce. Before the opening of the Lake Superior district, most blast furnaces owned their own small, local iron deposits. Few records of these operations survive. After the emergence of large-scale firms in the industry, the greater capitalization of the production end of the industry and the isolated locale of their iron mines resulted in few records of the ore mining part of the industry surviving. This proposal, by digitizing the records of a major iron ore mining firm, would make primary source material from one of the key inputs to the American industrial revolution widely available.
The transition of iron ore production to the mid-West was well underway during the Civil War. In 1860 Lake Superior mines had produced less than 5 per cent of American iron ore. By 1870 the proportion had tripled to over 16 per cent. By 1873, Pittsburgh furnaces (on the west side of the Alleghenies) universally used Lake Superior ores and could not compete in quality with imported iron without them. By 1880 Lake Superior mines would produce 30 per cent of American iron ore, with Michigan on the verge of becoming the nation's leading iron ore producing state, surpassing traditional leader Pennsylvania. By 1890 the Lake Superior district was producing over 50 per cent of American iron ore, rising to 75 per cent by 1900, when Minnesota surpassed Michigan as the leading ore producer.