When did maize, beans, and squash become domesticated in Middle America?

In Middle America (Mesoamerica), the domestication of corn, beans, and squash occurred over several millennia as part of a gradual transition to agriculture.

• Squash: Evidence indicates that squash was among the earliest plants domesticated in the region, with archaeological findings dating to approximately 8000–7000 BCE. Other evidence suggests domestication of certain squash varieties was occurring as early as 10,000 years ago.12
• Corn (Maize): While likely domesticated by native peoples about 10,000 years ago, corn appears in the archaeological record as a food source by 5000 BCE. By 5000–4000 BCE, it was being actively cultivated, and it underwent rapid development as a food plant in the following two to three millennia.231
• Beans: The cultivation of beans appeared later, with evidence showing their use after 3500 BCE.3

These three crops eventually became the foundation of the milpa system, an intercropping practice that dates back as many as 3,500 years among the Maya, with some evidence suggesting the practice may have been established in Mexico even earlier, between 7,000 and 4,400 years ago.45