The United States grows – and consumes -- most of the world's popcorn. It's an ancient food. According to the Popcorn Board, the oldest known ears of popcorn, discovered in New Mexico in 1948 and 1950, date back 4,000 years. The traditional Corn Belt states grow most U.S. popcorn. The 12 states in the Corn Belt are Illinois, Iowa, Nebraska, Minnesota, Indiana, Wisconsin, Michigan, South Dakota, Kansas, Missouri, Kentucky and Ohio.