There are mainly three types of peanuts grown in the United States- Virginias, Runners and Spanish peanuts. Virginias are often called cocktail nuts and are considered large-kerneled. A fourth type, Valencia peanuts, are grown less frequently in the US and are characterized by three or four small kernels in a long shell.
Peanuts actually grow underground, as opposed to nuts like walnuts, almonds, etc.
The peanut plant is thought to have originated in Brazil or Peru. Portuguese explorers transplanted it to Africa, and from there it was brought to America as an inexpensive, high-protein staple, later to be consumed by soldiers during the Civil War. George Washington Carver is considered by many to be the father of the peanut industry. He began his peanut research in 1903. He suggested to farmers that they rotate their cotton plants and cultivate peanuts.