Answer:
Maya
Step-by-step explanation:
Corn in fact was found WAY before the Mayan people dominated the current regions of Mexico and Guatemala.
Some traces of corn (and popcorn too!) were found in New Mexico dating back some 5,000 years ago. The Mayan civilization florished about 1200 years ago... but its descendants are still very present mostly in Guatemala.
The Incas in Peru were masters of the potatoes. In Peru, there are over 500 varieties of potatoes, and it's still a very important part of the diet down there.