Final answer:
Maize, known as corn in the U.S., was the most important domesticated plant in Ancient America, developed from teosinte. It became a central part of the diet throughout the Americas and greatly influenced global diets after the Columbian exchange.
Step-by-step explanation:
The most important of all domesticated plants in Ancient America was maize (commonly referred to as corn in the United States). This staple crop was developed from a wild grass called teosinte roughly 7,000 to 10,000 years ago in central Mexico. Over generations, particularly through the work of women farmers, teosinte was selectively bred into the larger, nutritious ears of maize that became a central food source throughout the Americas. Maize was so critical that it was one of the three staple crops of the Mesoamerican triad, which also included beans and squash. Beyond agricultural sustenance, maize played a crucial role in the diffusion of agricultural knowledge and techniques throughout the Western hemisphere.
As a staple crop, maize holds a prominent place in the top five staple crops in the world today, alongside rice, wheat, potatoes, and cassava. After Europeans arrived in the Americas, maize, along with other crops such as potatoes and cassava, were introduced to the Old World where they significantly altered diets and contributed to social changes including population growth and the Industrial Revolution.