Corn is one of the top grain commodities in the U.S. and grows throughout the nation, but most commonly on farms in the Heartland. Corn is harvested to make many different products such as feed for animals, starch, sweeteners, and ethanol fuel - a renewable fuel source that provides an alternative to gasoline and petroleum. The U.S. exports about twenty percent of its corn crop to other countries. The kind of corn that we enjoy "on the cob" is called sweet corn. Americans love to eat popcorn, leading the world in popcorn production and consuming 16 billion quarts annually.