Bulking Up The 20 years that separate these two maps were witness to perhaps the single most powerful and rapid alteration of life to ever be experienced on Earth. This is particularly true in America, but also clearly evident around the world. Electricity is the accelerating X-factor, following so closely on the heels of steam power and steel production.

	Saturation Point? The GREEN lines are the latest railroads, built since 1870, while PURPLE lines were built earlier. The new lines are mostly located west of Chicago, following the prevailing notion that railroads attract settlers, with business not far behind. Railroads attempt to lure settlers to dry prairie territory with misleading ads (lower left). In reality, the region lying west of the YELLOW dotted line is suitable for livestock, but crops will fail unless irrigated. Heading west, the land is first too dry, and then too mountainous.
	Water from Below By 1890, irrigation is helping farmers grow crops in dry western regions. BLUE highlights indicate areas where sparse rainfall is supplemented by irrigation ditches. Steam-powered pumps are needed to raise water up from rivers, where water level is always lower than the surrounding land (lower right). Even in areas where ground water gushes up under natural pressure (top right), a steam engine might still be needed to drill down to the source of the water.