"IT WAS in a valley somewhere in central Mexico at least 5,000 years ago that maize (corn, to Americans) was first domesticated. Many Mexicans see the crop as part of their national patrimony, much as potatoes are to Peruvians or pasta is to Italians. So it is understandable that when on January 1st import tariffs on maize (along with beans, sugar and milk) were finally eliminated, many Mexicans felt a twinge of regret. The end of the tariffs marked the culmination of a 14-year transition to free trade between Mexico, the United States and Canada under the North American Free-Trade Agreement (NAFTA)." (Quoted from article)