the great bulk of the material upon which the manufacturers of leather rely for their tannin. Advantages in securing this supply is one of the factors which determine the location of tanneries. This accounts for the enormous recent development of the industry in Wisconsin and some other States. Pennsylvania has twice the production of any other State, Massachusetts, New Jersey, and Wisconsin ranking next in order.
One of the most distinct triumphs of American industry has been made in the manufacture of boots and shoes. Probably no other industry has been so completely revolutionized. Previous to 1845 the industry was strictly a hand process; to-day the shoe factory provides a perfect system of continuous manufacture, involving, in some instances, more than 100 operations. Beginning with the leather-rolling machine, there followed rapidly the wax-thread sewing machine, the peg-making machine, and peg-driving machine, and other machines, of which the most important was the McKay sewing machine, which has perhaps done more to revolutionize the manufacture of shoes than any other single machine. Important inventions are continuously being added to the list. As a result there has been a decided centralization of the industry, the number of establishments having decreased from 2082 in 1890 to 1600 in 1900, and a decided increase in the number of wage-earners relative to the value of products. In 1900 the number of wage-earners was only about one-half greater than in 1850, whereas the value of products was nearly 6 times as great in the later as in the earlier year. There is also an increase in the number of women and children employed. Of the 142,000 factory hands in 1900, 47,186 were women and 4521 children. American shoes are exported in large quantities.
Until well along in the nineteenth century the industry was confined almost wholly to eastern Massachusetts, and that State produced over three-sevenths of the total product in 1900. For a number of years, however, the industry has been rapidly developing in other regions, and almost the entire gain for the decade 1890-1900 was made outside Massachusetts, there being a decided decrease of capital reported for that State. The largest increase was made in Ohio and Missouri, but New York and New Hampshire still rank second and third respectively.
The manufacture of saddlery and harness, particularly the latter, is widely distributed, being usually carried on by small establishments intended to supply the local demand. In the decade 1890-1900 there was a gain in the number of establishments amounting to 63.1 per cent. There is a greater centralization in the manufacture of pocketbooks, trunks, and valises. The manufacture of leather gloves and mittens employed 14,436 persons in 1900, of whom 9754 were women. The value of the product for that year was $17,048,656.
Slaughtering and Meat-Packing. In 1850 slaughtering and meat-packing was of little importance as a specialized industry, the value of the product for that year being only $11,981,642. Before 1890, however, the industry had become the most important of the industries manufacturing food products, and in 1900 was far in the lead, with a total value of products estimated at $785,562,433. There was a proportional increase in the capital invested, which amounted in 1900 to $189,198,264, this being less than the total capital invested in flour and grist milling. In the same year there were 68,534 persons employed. A number of factors have conspired to bring about this most remarkable expansion of the industry. The growth in stock-raising and the increase of the population are, of course, important considerations, but the development of the industry has been out of all proportion to either of these. Formerly much of the slaughtering was done by the stock-raiser himself, and the local supply sufficed in most communities. But as large centres of population, developed at a distance from the greater stock-raising regions, created a need for the packing and preserving of meats, a greater specialization of the industry, better facilities of communication, and the devising of processes of preservation and especially of refrigeration made this possible. The refrigerator car, first used in 1869, marked an epoch in the industry, since it made possible the shipment of fresh beef. Refrigeration made possible the continuation of the industry throughout the year, and shipments to foreign countries. (For meat exports, see section Commerce.) The exportation of fresh beef began in 1876. About the same time labor-saving devices were adopted and every part of the animal began to be utilized. The decade 1870-80 witnessed the first rapid specialization and centralization of the industry. During that period the value of products increased 300.3 per cent., while the number of establishments increased only 13.5 per cent. In the decade 1890-1900, although the value of products increased 39.9 per cent., the number of establishments decreased from 1118 to 921. The industry has tended to localize near the producing regions at points which have the greatest advantages of transportation. About 1850 the Ohio Valley was the great producing region, and the river towns, with Cincinnati and Louisville in the lead, were the centres of slaughtering and meat-packing. With the subsequent development of stock-raising in Illinois, Iowa, and other Upper Mississippi Valley States, together with the unequaled transportation advantages of Chicago, that city has attained an importance in slaughtering and meat-packing that is unapproached by any other city in the world. The value of products of 1890 was 36.3 per cent., and in 1900 32.7 per cent. of the total for the United States. The relative decrease is the result of the development of the industry in other centres, nearer to the producing region, especially Kansas City, South Omaha, Saint Joseph, Saint Louis, and elsewhere in the Southwest and Northwest. The packing of meats is almost wholly carried on west of the Alleghanies, but New York and other Atlantic Coast centres slaughter extensively for the local market. The value of the hogs slaughtered is considerably in excess of the value of beeves slaughtered. About five-sixths of the beef is sold fresh, while only about two-sevenths of the pork is sold in this form.
Transportation—Railways. The great industrial progress after 1850 was made possible largely by railways. The construction of railways in the United States began toward the close of the decade 1820-30. Their introduction had been preceded by the inauguration of a vast system of canals, the Erie Canal, which was to remain long the principal artery of transportation
