Industry executives are nonetheless worried that the episode could hurt American corn and food exports.
However the adoption of free trade in mid-19th century brought cheap American corn which undersold local farmers.
He was impressed with American corn, which was 30 times better than the Korean one at the time.
Many Zambians question the government's statements and wonder why friends who received the American corn before the ban went into effect have not died.
Japan, the biggest foreign buyer of American corn, has about 1.3 million tons in storage.
Over all, imports of American corn, mostly for animal feed, have stayed steady.
The scene depicted on the coin is one of a native American planting corn.
It is true that biofuels have caused an increase in the price of American corn.
Foreign sales of American corn and corn products exceed $1 billion a year.
Unlike Japan, however, Europe is not a significant importer of American corn.