In these years urbanization also went forward rapidly. Cities of the east grew fantastically, and even in the interior cities rose from wilderness outposts to gigantic metropolises. Within one man's lifetime Chicago increased from 350 people in 1830 to 1,099,000 in 1890. Simultaneously, tremendous developments in transportation kept the nation and its economy tied together. All of these developments had a profound influence on farming and farmers. The rich cities provided ever greater markets for the farmers' produce. The transportation system, rapidly moving farm commodities, made farming profitable in remote regions far distant from the coast. Farmers also felt the advantages of the return flow of goods and services: the mail order catalog, the industrially made reapers and threshers, and countless other items. City people made a countless range of devices for farmers—from steel plows to steam engines.
Meanwhile, as these events altered the life of the farmer, a burst of activity took place in invention and discovery. These activities had a delayed but considerable impact on farm methods and technology. The list of inventions and discoveries could hardly fit in this narrative, but this catalog of items reflects fairly well what men accomplished in the 19th century. The changes included such diverse elements as the invention of the cotton gin by Eli Whitney in 1793, the introduction of Mexican Upland cotton in 1805, the discovery of the cause of Texas fever in cattle in 1889, and the invention of the internal combustion tractor in 1892. These and many other achievements substantially changed the farm enterprise in two major directions: first, advances in technology allowed farmers to do more in less time; second, discoveries in science allowed farmers to increase the yield from the land. Farmers got more from each acre, plant, and animal.
Farmers could use the savings in time brought by better implements and new machines to increase the amount of land farmed and the number of animals cared for. Presumably, the farmer could also use the saved time for greater leisure. In fact, however, they usually used the extra time for more work. In the 20th century they often used the saved time for outside employment. Farmers did this in the 19th century, but not so commonly as later. Greater man-hour efficiency gave the farmer more time to devote to managing his enterprise, to keeping records, and to studying his business.
Technological efficiency also allowed farmers to use more land and more animals. The average size of farms steadily increased across the century. Furthermore, the new machines and the pure-bred livestock cost money which could be most profitable only if the farmer specialized in one, or at most two, types of enterprise. So the greater efficiency created by technology impelled farmers to greater specialization, and with specialization came even greater efficiency. Anyone who specializes will likely be more efficient because of the mastering of skills. He will also have a minimum of other cares to distract him. Of course, for the consumers, foreign or domestic, greater farming efficiencies resulted in abundant food at comparatively low cost.
Plant and animal importation, improvement of breeds, and discoveries in genetics, soil chemistry, the use of fertilizers, and in controlling plant and animal diseases all helped the living things which form the basis of farming yield. Grain farmers not only had to have a wheat which yielded well but a wheat which resisted the attacks of nature. For example, Turkey Red wheat, introduced in 1873 by Mennonites from Russia, not only survived drought and yielded well but provided the genetic elements for newer breeds of wheat. The farmer not only wanted good-producing meat cattle, such as the Herefords, but had to control diseases and predators which killed the animals. Sick animals do not grow properly or, in the case of dairy animals, give much milk. Steady advances in disease control for both plants and animals brought fewer losses and greater productivity to farmers.
The 19th century also brought scientific discoveries in both plant and animal nutrition. Fertilizer and soil chemistry made great advances through scientific experiments, at first by farmers and later by government servants. The first experiment station in the modern era began in Connecticut in 1875, and in 1887 the Congress established such stations in every state in conjunction with the agricultural Land Grant colleges. Scientists at many of the stations also made discoveries in animal nutrition. For example, as a result of animal feeding experiments E. V. McCollum discovered vitamins A and B at the experiment station in Wisconsin in 1915.
None of these scientific advances left much residue in the form of artifacts for museums, but the reality of the changes should not be obscured by the lack of objects on exhibit. Even so, some of the related equipment survived. For example, the centrifuge used in the butterfat test, discovered in 1890 by Stephen M. Babcock, survived in several forms. Manure spreaders and tree sprayers, reflective of advances in biochemistry, also survived. But these only suggest the more important biological control activities for which these machines and tools served merely as agents in some way.
The 20th century introduced Americans to total war. World Wars I and II demanded the total mobilization of all resources by all contenders. In both conflicts America became the food reservoir of the Allies. From a technological view, the wars engendered a level of prosperity which both allowed and encouraged farmers to adopt new methods and devices. The principal technological change in farms was the widespread adoption of the internal combustion tractor, first used in 1892. Inventors and manufacturers gradually but constantly improved tractors along with the various devices attached to them. Most notable were the corn picker, in 1909, and the cotton picker, in 1942. (Dates are for commercial production in each instance.) Farmers found both machines impracticable until a power source independent of the ground wheel had been developed. More than anything else the tractor and its related equipment finally set men free from the worst drudgery of farming. It also set many farmers free from the need to farm at all.
The tractor and its equipment accomplished several other remarkable things, some obvious and some not so obvious. First, it allowed the farmer to get rid of horses and mules, and these animals steadily declined—to such an extent that in the 1960s the census did not even bother to count them. As a result of this decline, land that farmers had used to raise feed for animals could grow food for people or fodder for dairy animals. The amount of land thus released for other needs finally amounted to perhaps 60 million acres, and maybe even more. The change took place with increasing rapidity into the 20th century.
Also, the tractor sharply reduced labor needs for the major crops of the United States. Even dairying, least susceptible to this sort of improvement, felt the impact of the tractor in such things as harvesting fodder and storing silage by running loaders off the tractor power-take-off. Since the very founding of agriculture men had discovered only one way to prosper in farming. The farmer had to exploit somebody or something. Animals, serfs, slaves, tenants, sharecroppers, or whatever, including the farmer's family and farm, had at various times been exploited on the farmer's way to success. After the age of machinery, however, the farmer tended to exploit the machine instead of other people or things. People had to leave farming, but in the long run they benefited from their removal. The machine had set them free. Chief of the machines was the gasoline tractor.