Wikipedia Reference Information
Agriculture is a major industry in the United States and the country is a net exporter of food.
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 through the use of slave labor until the Civil War. In the northeast, slaves were used in agriculture until the early 19th century. In the Midwest, slavery was prohibited by 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 land 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 complete, up-to-date and editable article about USA Agriculture can be found at Wikipedia: USA Agriculture