The North American Free Trade Agreement (NAFTA) was signed on August 12, 1991. It was signed by the heads of state of the United States of America, Canada, and Mexico. However, the treaty did not go into effect immediately after it was signed. Instead, the treaty had to be ratified by the various countries that signed it. Therefore, the treaty did not go into effect until January 1, 1994. At that point, it became law and created a free trade zone out of the three countries of North America. The treaty remains in effect today and has no expiration date.