"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. The major field crops with the value of production (in $billions) are:
Source: 1997 USDA-NASS reports, http://www.usda.gov/nass/pubs/ranking/rankus-b.txt. *=data not available. Fruits, vegetables, and nut crops excluded. Livestock
The major livestock industries in the United States are:
Inventories in the United States at the end of 1997 were: 403,000,000 chickens 99,500,000 cattle 59,900,000 hogs 7,600,000 sheep
Goats, horses, 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.
Soybeans were not widely cultivated in the United States until the 1950s, when soybean acres began to replace oats and wheat acres.