Corn already existed in North and South America. As a matter of fact it was considered a sacred food by the indian tribes, and was presented by them to the first European explorers. However, when Cortez arrived in Mexico, instead of corn, the indians presented him with gold. Why? because they knew what white men were after. How? Although history says nothing about it, the indians had learned it from contacts with previous explorers, although Cortez is still considered as being the first.