Question: アメリカの農園労働者・奴隷たちは主に何を主食としていた？
Context: Wheat, used for white bread, pastries, pasta, and pizza, has been the principal cereal crop since the 18th century. It was introduced by the first English colonists and quickly became the main cash crop of farmers who sold it to urban populations and exporters. In colonial times its culture became concentrated in the Middle Colonies, which became known as the "bread colonies". In the mid-18th century, wheat culture spread to the tidewaters of Maryland and Virginia, where George Washington was a prominent grower as he diversified away from tobacco. The crop moved west, with Ohio as the center in 1840 and Illinois in 1860. Illinois replaced its wheat with corn (which was used locally to feed hogs). The invention of mechanical harvesters, drawn first by horses and then tractors, made larger farms much more efficient than small ones. The farmers had to borrow money to buy land and equipment and had to specialize in wheat, which made them highly vulnerable to price fluctuations and gave them an incentive to ask for government help to stabilize or raise prices. Wheat farming depended on significant labor input only during planting, and especially at harvest time. Therefore, successful farmers, especially on the Great Plains, bought up as much land as possible, purchased very expensive mechanical equipment, and depended on migrating hired laborers at harvesting time. The migrant families tended to be social outcasts without local roots and mostly lived near the poverty line, except in the harvesting season. From 1909 to today, North Dakota and Kansas have vied for first place in wheat production, followed by Oklahoma and Montana.
In the colonial era, wheat was sown by broadcasting, reaped by sickles, and threshed by flails. The kernels were then taken to a grist mill for grinding into flour. In 1830, it took four people and two oxen, working 10 hours a day, to produce 200 bushels. New technology greatly increased productivity in the 19th century, as sowing with drills replaced broadcasting, cradles took the place of sickles, and the cradles in turn were replaced by reapers and binders. Steam-powered threshing machines superseded flails. By 1895, in Bonanza farms in the Dakotas, it took six people and 36 horses pulling huge harvesters, working 10 hours a day, to produce 20,000 bushels. In the 1930s the gasoline powered "combine" combined reaping and threshing into one operation that took one person to operate. Production grew from 85 million bushels in 1839, 500 million in 1880, 600 million in 1900, and peaked at 1.0 billion bushels in 1915. Prices fluctuated erratically, with a downward trend in the 1890s that caused great distress in the Plains states.
The marketing of wheat was modernized as well, as the cost of transportation steadily fell and more and more distant markets opened up. Before 1850, the crop was sacked, shipped by wagon or canal boat, and stored in warehouses. With the rapid growth of the nation's railroad network in the 1850s–1870s, farmers took their harvest by wagon for sale to the nearest country elevators. The wheat moved to terminal elevators, where it was sold through grain exchanges to flour millers and exporters. Since the elevators and railroads generally had a local monopoly, farmers soon had targets besides the weather for their complaints. They sometimes accused the elevator men of undergrading, shortweighting, and excessive dockage. Scandinavian immigrants in the Midwest took control over marketing through the organization of cooperatives.
Answerable: yes
Answer: Wheat