THE IMPLEMENTATION of the North American Free Trade Agreement (NAFTA) in 1994 opened borders to trade between the United States, Canada, and Mexico. The agreement originated from the free trade agreement the United States and Canada signed in 1988. NAFTA eliminates almost all barriers to trade and investment between the three North American countries and includes provisions for the protection of intellectual property rights. Certain trade barriers for agricultural products remain under NAFTA—notably, products under supply management in Canada (dairy, eggs, and poultry).