Peanuts originated in South America, most likely in what is now Bolivia, where indigenous peoples first domesticated them thousands of years ago. Archaeological evidence of wild peanut cultivation dates back roughly 10,000 years in Peru, and the earliest confirmed remains of the domesticated peanut species are around 5,000 years old. From that starting point in South America, peanuts eventually traveled to every inhabited continent, becoming one of the world’s most important crops.
The Wild Ancestors in South America
The peanut we eat today is a hybrid. Its wild ancestors grew in the lowlands and foothills east of the Andes, in a region spanning parts of modern Bolivia, Paraguay, and northern Argentina. Indigenous peoples in this area were the first to cultivate and eventually domesticate the plant, selecting for larger pods and better yields over many generations.
The dry climate of coastal Peru has preserved some of the oldest physical evidence of this process. Starch grains and plant remains attributed to the cultivation of wild peanut species have been dated to roughly 10,000 years ago. In the Ñanchoc Valley on the lower western slopes of the Andes in northern Peru, a research team from Vanderbilt University found peanut remains dating to about 7,600 years ago, alongside ancient squash and cotton. The earliest remains positively identified as the fully domesticated species were found at sites in Peru dating to around 5,000 years ago. Researchers identified them by the distinctive reticulated patterns on the pod shells.
East of the Andes, where the climate is wetter, similar cultivation was almost certainly happening at the same time. But wet conditions break down plant material quickly, so the archaeological record there is far thinner. The Peruvian finds survive precisely because the region is so arid.
How Peanuts Grow Underground
One reason peanuts are so unusual is that they bury their own seeds. The plant flowers above ground like most plants, but after pollination, something strange happens. A structure called a peg grows downward from the base of the flower, pushing the developing pod into the soil. The peanut then matures entirely underground. This process, called geocarpy, is rare in the plant kingdom and is one reason peanuts are sometimes mistaken for root vegetables or tubers rather than legumes (they’re in the same family as beans and lentils).
This underground growth habit likely evolved as protection against heat, drought, and animals that would eat the seeds. It also means peanuts need loose, sandy, well-drained soil to thrive, which influenced where they were historically grown and where they’re farmed today.
Spreading Across the Americas
Long before Europeans arrived, indigenous trade networks carried peanuts far from their Bolivian homeland. They spread west into Peru, east into Brazil, and north through Central America and into Mexico. By the time Spanish conquistadors arrived in the Americas after 1519, peanuts were already a well-established crop across a wide swath of the continent. Indigenous peoples ate them roasted, ground them into pastes, and used them in stews.
From the Americas to the Rest of the World
Spanish and Portuguese explorers encountered peanuts in the 16th century and carried them back across the Atlantic. The Portuguese, who found peanuts in Brazil, introduced them to West Africa, where they adapted remarkably well to the tropical climate and soils. Peanuts quickly became a dietary staple across much of the continent, so thoroughly integrated that many people today assume peanuts are native to Africa.
The Spanish brought peanuts to Europe and the Philippines, and from there the crop spread across Southeast Asia and into China. Within a few centuries of European contact, peanuts had circled the globe.
The Roundabout Path to North America
Peanuts didn’t travel directly from South America to what is now the United States. Instead, they took a long detour through Africa. As the transatlantic slave trade expanded, peanuts were brought into the Caribbean as food for enslaved people on ships and plantations. From the Caribbean, they migrated into the southern British colonies of North America during the mid-1700s.
For a long time, peanuts were considered food for the poor. Native Americans and poor white farmers in the South ate them, and they had little commercial prestige. Southern farmers eventually began exporting them to northern cities, where roasted peanuts became one of the first popular street snacks in the United States. The Civil War played an unexpected role in boosting peanuts’ popularity: both Union and Confederate soldiers ate them as a cheap, portable source of calories, and returning soldiers brought a taste for them back home.
By the early 20th century, agricultural scientist George Washington Carver championed the peanut as a versatile crop that could restore nitrogen to soil depleted by cotton farming. He developed over 300 uses for peanuts, from shaving cream to wood stains to plastics, helping transform peanuts from a humble snack into a significant agricultural commodity.
Where Peanuts Are Grown Today
China is now the world’s largest peanut producer, followed by India and Nigeria. The United States ranks fourth. The geography of modern production reflects how thoroughly peanuts adapted to tropical and subtropical climates around the world after leaving South America. In the U.S., most peanuts are grown in Georgia, Texas, Alabama, and the Carolinas, where the sandy soils and long warm seasons suit the plant’s underground fruiting habit.
It’s a striking arc for a plant that started as a wild legume in the foothills of Bolivia: today peanuts are grown on every continent except Antarctica and are a critical source of protein and fat for billions of people.