The country life itself began to change. The typical farming families, developed by pioneer conditions, had remained the social unit for several generations, but these felt the lure of the cities which drew their boys and girls into the factories. Domestic manufactures could not compete in quality, appearance, or price with the output of the new factories. The farmer began to give up his slaughtering and butter-making, as he had already abandoned his spinning and weaving, and devoted himself more exclusively to raising crops. Here, too, the mechanical improvements touched his life. Agricultural machinery was coming into general use, while the new railroads carried off his produce to the great markets which the rising cities created. The number of employees of American factories increased more than half between 1860 and 1870, while the capital invested and the goods turned out were more than doubled. The United States was for the first time looking to a day when all the ordinary necessities of life could be made within its limits. At Chicago, St. Louis, New York, Boston, Philadelphia, and a host of cities in the interior, men were not disturbed by the war in their attempt to exploit the abundant resources of the continent. The manufacture of food began to shift from the household to the city factory, to the advantage of the cities lying near the great fresh areas of farm lands. The flour mills of the Northwest, the meat-packing establishments at Chicago and elsewhere, the distilleries of central Illinois, utilized the agricultural staples and transformed them for export. The presence of factories forced upon the city governments, East and West, already embarrassed by the pains of rapid growth, the problems of police power and good government. Charters written for semi-rural villages were inadequate when the villages became cities. Clothing, no less than food, passed into the factory, thanks to Elias Howe and his sewing-machine and the shoe machinery of McKay. Before the war the influences of this change were visible in the increasing demand for cotton. Now came the great growth of the textile regions of the East, around Fall River and Philadelphia, and of the shoe factories in the Lynn district. The use and manufacture of machines gave new stimulus to those regions where coal and iron, placed conveniently with reference to transportation, had fixed the location of smelters and rolling-mills. In the middle of the sixties Henry Bessemer's commercial process for the manufacture of steel marks the beginning of a revolution in the construction of railroads and bridges, as well as in public and private architecture. Pittsburg became the heart of the steel industry, and the young men who controlled it fixed their hands upon the commercial future of the United States. The newest of industries, the trade in petroleum and its oils, reached fifteen millions in Pittsburg alone in 1864.