latter have become comparatively unimportant, as will be seen in the preceding table.
To this should be added in 1901 Wisconsin and Tennessee each with over 700,000 tons, and Colorado and New Jersey with over 400,000 tons each. The development of the Lake Superior iron region is one of the most significant of recent industrial movements in the United States. It has been rendered possible largely through the advantage afforded by the Great Lakes for transportation. With the improvement of the canals connecting the lakes and the increased tonnage of vessels there has been a resulting decrease in freight rates and a greater impetus given to the mining industry. (See section on Transportation.) The industry has also profited by the improved methods adopted to facilitate the transfer of the ore in transit and especially by the use of machinery and the mining operations themselves. Furthermore, in the principal mining range—Mesabi—the ore is sometimes found so near the surface that with the removal of a few feet of earth it is mined by the open-pit method, the ore being scooped by huge steam shovels directly from the pit to the car. Probably in no other mines in the world does massive machinery play so great a part in mining operations and hand labor so little. Work in the Mesabi Range began in 1892, and the output grew rapidly until 1901, when it amounted to 9,303,541 long tons. The Southern iron region shares with the Northern Appalachian region in the advantage of having coal and limestone, two essentials in the reduction of the ore and found in close proximity to the ore itself. The South has the additional advantage of cheap labor, but it is under the disadvantage of having a limited local market.
Gold. The mining of gold on an extensive scale did not begin until the discovery of the placer gold in California in 1848. Between 1820 and 1830 some interest had developed in the States of Virginia and North and South Carolina, and for a number of years the output averaged about $1,000,000. In 1850, within two years after the California discoveries, the output was $50,000,000, and it did not fall below this figure until 1860. The product greatly exceeded in total value the value of all other minerals mined during that period. The gold output has ever since been large, though subject to fluctuation. As ordinary placer mining began to be unprofitable, quartz mining and hydraulic mining were resorted to, and California continued to be an important gold-mining State. The working of placer mines in Montana between 1860 and 1870 helped greatly to sustain the high record which California had earlier established. Montana being credited in one year (1866) with an output valued at $16,500,000. Considerable amounts were contributed also by other Western States, particularly by Nevada, owing to the Comstock Lode. With the exception of two years the annual output from 1871 to 1895 stood below $40,000,000. With the decline in the value of silver, attention was turned to gold. Improved methods of mining and of extracting the metal from the ores reduced the cost, and made possible the working of mines that were unprofitable under the old methods. Almost every Western mountain State has shared in the increase that raised the total output of gold from $33,000,000 in 1892 to $78,666,700 in 1901. Colorado took first rank in 1897 and in 1901 produced $27,693,500. California ranked second with an output of $16,891,400. South Dakota, Utah, and Arizona are three of the most rapidly developing sections. Alaska's (q.v.) contribution in 1901 was $6,885,700.
Silver. The development of silver-mining in the United States was almost as sudden as was that of gold. The production of this metal had been quite insignificant until the discovery of the Comstock Lode (q.v.) in western Nevada in 1859. The United States then became the leading silver-mining country of the world. The only other nation that now competes with it in this industry is Mexico. The output of the Comstock Lode declined rapidly after 1877. Nevertheless other mines were developing, and the silver product of the country continued to increase. The two largest contributors to this increase were the lead mines of Colorado and later the copper mines of Montana, large quantities of silver being extracted from both the lead and the copper ores. The total output, after falling to 49,501,122 ounces in 1894, had increased to 59,653,788 ounces in 1901, the commercial value of which at the mines was $35,792,200. Over one-third of the total product in the latter year was produced by Colorado, Montana and Utah yielding the greater part of the remainder.
Copper. Very little copper was mined prior to the development of the Lake Superior copper mines, which began operations in 1845. From that year the product has continued to increase steadily and rapidly. In 1866 the famous Calumet and Hecla mine was opened, and in 1890 its annual product had grown to 59,868,106 pounds, and in 1901 to 82,519,676 pounds. In 1880 Lake Superior ores furnished 82.2 per cent, of the total product of the country. About this time Arizona began to figure prominently in copper-mining, and a little later Montana also, the latter advancing so rapidly that in 1885 it produced 40.9 per cent. of the total product, as against 43.5 for Lake Superior and 13.7 for Arizona. Though the Lake Superior output continued to increase, its per cent. of the total had fallen to 25.9 in 1901. Montana more than doubled its output in the decade ending 1901, producing in that year 38.2 per cent. of the total product, while Arizona increased its output three and one-half times in the same period, having 21.7 per cent. of the total product in 1901. In the last years of that decade California and Utah rapidly advanced in their output of copper. The principal Montana mines are located at Butte, the largest mining centre in the world. The Anaconda mine produced, in 1901, 101,850,224 pounds, and the Boston and Montana nearly half that amount. In Arizona the Copper Queen yielded 39,781,133 pounds, and the United Verde 34,520,695 pounds. The total output for the United States increased from 27,000 long tons in 1880 to 115,966 in 1890, and 268,782 long tons in 1901, these amounts being respectively 17 per cent., 43 per cent., and 53 per cent, of the world's product. The value of the output in 1901 was $86,629,266. The United States is now the controlling factor in the world's copper markets.
Lead. The United States ranks first among the countries of the world in the production of lead. The mining of this mineral began as early as 1720 in the southeastern part of what is now
