THE RANCHES.--Stretching across the country from Montana and Dakota to Arizona lay the grass region, the great ranch country, where herds of cattle grazed and were driven to the railroads to be taken to market. In later years this became also the greatest sheep-raising and wool-producing region in the Union. BUFFALOES AND INDIANS.--With the building of the railroads and the coming of the settlers the reckless slaughter of the buffalo and the crowding of the Indians began. [11] To-day the buffalo is as rare an animal in the West as in the East; and after many wars and treaties with the Indians, they now hold less than one hundredth of the land west of the Mississippi. [Illustration: CUSTER'S FIGHT.] MECHANICAL PROGRESS.--The period 1860 to 1880 was one of great mechanical and industrial progress. During this time dynamite and the barbed-wire fence were introduced; the compressed-air rock drill, the typewriter, the Westinghouse air brake, the Janney car coupler, the cable car, the trolley systems, the electric light, the search light, electric motors, the Bell telephone, the phonograph, the gas engine, and a host of other inventions and mechanical devices were invented. To satisfy the demands of trade and commerce, great works of engineering were undertaken, such as twenty years before could not have been attempted. The jetties constructed by James B. Eads in the South Pass at the mouth of the Mississippi, to force that river to keep open its own channel; the steel-arch railroad bridge built by Eads across the Mississippi at St. Louis; the Roebling suspension bridges over the Ohio at Cincinnati and over the East River at New York; and the successful laying of the Atlantic cable (1866) by Cyrus W. Field, are a few of the great mechanical triumphs of this period. INDUSTRIAL DEVELOPMENT.--Industries once carried on in the household or in small factories were conducted on a large scale by great corporations. The machine for making tin cans made possible the canning industry. The self- binding harvester and reaper made possible the immense grain fields of the West. The production and refining of petroleum became an industry of great importance. The great flour mills of Minneapolis, the iron and steel mills of Pennsylvania, the packing houses of Chicago and Kansas City, and many other enterprises were the direct result of the use of machinery. [Illustration: STEEL MILL.] RISE OF GREAT CORPORATIONS.--Trades and occupations, industries of all sorts, began to concentrate and combine, and large corporations took the place of individuals and small companies. In place of many little railroads there were now trunk lines. [12] In place of many little telegraph companies, express companies, and oil companies there were now a few large ones. [Illustration: SETTLED AREA IN 1880.]