In the U.S., farms spread from the colonies westward along with the settlers. In cooler regions, wheat was often the crop of choice when lands were newly settled, leading to a "wheat frontier" that moved westward over the course of years. Also very common in the antebellum midwest was farming corn while raising hogs, complementing each other especially since it was difficult to get grain to market before the canals and railroads. After the "wheat frontier" had passed through an area, more diversified farms including dairy cattle generally took its place. Warmer regions saw plantings of cotton and herds of beef cattle. In the early colonial south, raising tobacco and cotton was common, especially slave labor until the Civil War. In the northeast, slaves were used in agriculture until the early 19th century, and in the Midwest, slavery was prohibited from the beginning since the Freedom Ordinance of 1787.
Soybeans were not widely cultivated in the United States until the 1950s, when soybeans began to replace oats and wheat.
Significant areas of farmland were abandoned during the Great Depression and incorporated into nascent national forests. Later, "Sodbuster" and "Swampbuster" restrictions written into federal farm programs starting in the 1970s reversed a decades-long trend of habitat destruction that began in 1942 when farmers were encouraged to plant all possible acreage in support of the war effort. In the United States, federal programs administered through local Soil and Water Conservation Districts provide technical assistance and partial funding to farmers who wish to implement management practices to conserve soil and limit erosion.
The only other crops to ever appear in the top twenty in the last 40 years were, commonly, tobacco, barley, and oats, and, rarely, groundnuts, almonds, and sunflower seeds (in all, only 26 of the 188 crops the FAO tracks). Alfalfa and hay would both be in the top ten in 2003 if they were tracked by FAO.
Goats, horses, turkeys and bees are also raised, though in lesser quantities. Inventory data is not as readily available as for the major industries. For the three major goat-producing states (AZ, NM, and TX) there were 1,200,000 goats at the end of 2002. There were 5,300,000 horses in the United States at the end of 1998. There were 2,500,000 colonies of bees at the end of 2002.