The document describes four major crop belts in the United States: the Corn Belt, which extends from Iowa to Ohio and has good climate and soil for growing corn as animal feed; the Dairy Belt from the Saint Lawrence River to the Great Lakes, which has a wet, cool climate suitable for crops to feed dairy animals; the Wheat Belt from Alberta to Texas, which has a dry, variable climate and uses extensive crop rotation and fallow periods to grow wheat; and the Cotton Belt from Texas to North Carolina, where cotton and other crops from the era of slavery are traditionally grown.