half times as much coal as the United States. In 1899 it was surpassed for the first time by the United States, and in 1901 the United States led by 42,790,730 tons. American coal is more easily mined than the coal of most countries, and the product sells at the pit cheaper than pit coal sells in any other part of the world. The total value of bituminous coal in 1901 was $236,201,899, and of anthracite $112,504,020. It will be seen from the above table that the Appalachian region has always contributed the bulk of the product. In spite of the enormous absolute gain in Pennsylvania, its relative importance has declined. West Virginia and Alabama are two of the fastest developing coal-mining States. The greater development of the Appalachian region is not due to the greater abundance of resources, although the quality of the Eastern product is generally superior to that of the West. It is due rather to convenience to the market. The thickly populated region to the north and east of Pennsylvania is without coal, and a large part of the anthracite product is consumed in that region for household purposes. Pennsylvania is also the most convenient coal-producing State so far as nearness to the industrial centre of the country is concerned, and a large part of its bituminous product is consumed in its own large iron manufacturing and railroad establishments. Its proximity to the shipping facilities of the Ohio River early gave it a command over the markets reached by the Ohio and Mississippi waterways. The want of a local market and the lack of railroad facilities have been against the development of the southern Appalachian coal region.
Petroleum. The production of petroleum began in western Pennsylvania in 1859. The United States soon became the chief source of the world's supply of this article. The recent development in Russia, however, has since 1897 placed that country ahead of the United States in rank. The production of the country increased slowly to 6,293,194 barrels in 1872, and then more rapidly to 45,823,572 barrels in 1890, and 69,389,194 barrels in 1901, the value in the last year being $66,417,335. The output in Pennsylvania reached its maximum in 1891, when it amounted to 33,009,230 barrels. Since that year the product has declined in that State until in 1901 it was only 12,625,378 barrels. About 1886 Ohio came into prominence in the production of petroleum, the output advancing rapidly to 17,740,301 barrels in 1891, and 21,648,083 barrels in 1901. The petroleum industry began early in West Virginia, but did not develop rapidly until in the last decade of the nineteenth century, the output increasing from 492,578 barrels in 1890 to 14,177,126 in 1901. The industry also developed slowly in California until 1899, increasing its output more than twofold in the following two years, the product in 1901 being 8,786,330 barrels. The production in Indiana did not begin until 1889, but has advanced steadily until 1901, when it amounted to 5,757,086 barrels. The last State to develop its resources of petroleum is Texas, the output having advanced from 50 barrels in 1895 to 4,393,658 barrels in 1901. In 1902 and 1903 important discoveries were made in Louisiana which is destined to become a large producer of petroleum. See Map under Petroleum.
Natural Gas. Natural gas has been extensively exploited in some parts of the United States in recent years. It began to come into use in western Pennsylvania after 1875, and by 1880 the value of the product for that State was estimated at $19,282,375. The production then declined until its value was less than one-third this amount, but revived during the four years ending with 1901, the production in that year being valued at $12,688,161. After 1885 Ohio and Indiana began to produce large quantities, but there was an early decline in Ohio, the value of the output in that State in 1901 being only $2,147,215, while Indiana more than held its own, the value for the same year being $6,954,566. Since 1895 extensive developments have occurred in Kansas and West Virginia. The total value of the natural gas for 1901 was estimated at $27,067,500, an amount twice as great as the reported value for 1897.
Production of Iron in Long Tons
| 1850 | 1870 | 1891 | 1901 | |
| Minnesota | ............ | ............ | 645,105 | 11,109,537 |
| Michigan | 2,700 | 859,507 | 6,127,001 | 9,654,067 |
| Alabama | 1,838 | 11,350 | 1,986,830 | 2,801,732 |
| Pennsylvania | 877,283 | 2,337,286 | 1,272,928 | 1,040,684 |
| Virginia and West Virginia | 67,319 | 84,108 | 665,116 | 925,394 |
| New York | 46,385 | 446,945 | 1,017,216 | 420,218 |
Iron. Iron-mining ranks in importance next to coal, iron ore, like coal, being very widely distributed in the United States. In 1901 25 States reported its production. The mining of iron began in early colonial days and it was the first mineral mined in the country. However, it did not rise into importance until near the middle of the nineteenth century. From a total output in that year of 1,560,442 long tons there was a steady increase to 5,250,402 long tons in 1870, 16,276,584 long tons in 1890, and 28,887,479 long tons in 1901, valued at the mines in the last-named year at $49,256,245. The production of pig iron exceeded that of Great Britain for the first time in 1890, and in 1902 was over twice as great, and equaled the combined output of Great Britain, Germany, and Belgium. Of the total output in 1901 the red hematite variety amounted to 24,006,025 long tons, brown hematite 3,016,715, the magnetite 1,813,076, and the carbonate 51,663 long tons. The Lake Superior ore is almost wholly of red hematite variety. The Virginias are the largest producers of brown hematite. Pennsylvania and New Jersey yield the largest quantities of magnetite. Alabama and Tennessee produce considerable quantities of both red and brown hematite. Prior to 1870 Pennsylvania was the chief iron-producing State, and yielded in that year 44 per cent. of the total product. This and other States east of the Appalachian Mountains produced 62 per cent. of the output for that year. Since then other regions have so far outstripped Pennsylvania and other Eastern States that the
