Antonio Cartin, left, and Miguel Hernandez load boxes of avocados for shipment Wednesday from Mexico City to the United States. The last time Americans legally ate imported Mexican avocados was 1914. During four winter months, 19 U.S. states, not including prime consuming states like Florida, California and Texas, will be open to Mexican imports. U.S. farmers contend the trade ban was needed to prevent pest infestation. Mexican farmers claimed the ban was aimed at keeping prices high.