Groundnuts are thought to have originated in South America, where they thrive in tropical and subtropical climates. The name “groundnut” is misleading, because it is not botanically a nut, but rather a legume. The edible seeds of a peanut plant start above ground but mature underground; thus peanuts are also known as groundnuts.
In the United States, peanuts were considered a regional food of the South until after the Civil War, when technological advancements resulted in an increased demand for peanut oil, peanut butter, roasted and salted peanuts, and confections. In addition, the noted scientist George Washington Carver identified numerous manufactured nonfood uses for the peanut and plant parts and encouraged plantings of peanuts as a rotational crop for cotton production, which expanded acreage in the early 1900s.