Although the oldest ears of corn are from Mexico, dating to at least 2750 BC, and still a staple food in all central American diets, the United States grows and consumes 16.65 TIMES as much corn as all of Mexico annually, fully 40% of the world's corn harvest.
That doesn't include our corn imports from many other countries, including Mexico.
We are the only country on Earth that uses it for such a wide variety of uses, including starch, liquor, livestock feed, fabrics, chemicals, plastics, biofuel, and of course food and food sweeteners. Fully 90% of American prepared foods have some kind of corn-derived sweetener in them such as Maltodextrin or High-fructose corn syrup!
This is because of seriously heavy US government incentives at the end of the Great Depression that continues through today.
Corn is so cheap and overused that our farmers feed it to our cows as the main source of feed... Instead of grass, which is more expensive but much easier to digest.
Sound like corn is a miracle plant?
It's not the plant's doing. Corn kernels are nothing but a pocket of starch. The US Government Incentives are what gets all the glory here, spending billions on researching uses for this one plant.
Meanwhile the raw potential of soybeans far surpasses that of corn and would have been a much better choice for them to focus on. Oh well.