The North American Free Trade Agreement (NAFTA) entered into force on January 1, 1994. The agreement was signed by President George H. W. Bush on December 17, 1992, and approved by Congress on November 20, 1993. The NAFTA Implementation Act was signed into law by President William J. Clinton on December 8, 1993 (P.L. 103-182). The overall economic impact of NAFTA is difficult to measure since trade and investment trends are influenced by numerous other economic variables, such as economic growth, inflation, and currency fluctuations. The agreement likely accelerated and also locked in trade liberalization that was already taking place in Mexico, but many of these changes may have taken place without an agreement. Nevertheless, NAFTA is significant, because it was the most comprehensive free trade agreement (FTA) negotiated at the time and contained several groundbreaking provisions. A legacy of the agreement is that it has served as a template or model for the new generation of FTAs that the United States later negotiated, and it also served as a template for certain provisions in multilateral trade negotiations as part of the Uruguay Round. The 115th Congress faces numerous issues related to NAFTA and international trade. President Donald J. Trump has proposed renegotiating NAFTA, or possibly withdrawing from it. Congress may wish to consider the ramifications of renegotiating or withdrawing from NAFTA and how it may affect the U.S. economy and foreign relations with Mexico and Canada. It may also wish to examine the congressional role in a possible renegotiation, as well as the negotiating positions of Canada and Mexico. Mexico has stated that, if NAFTA is reopened, it may seek to broaden negotiations to include security, counter-narcotics, and transmigration issues. Mexico has also indicated that it may choose to withdraw from the agreement if the negotiations are not favorable to the country. Congress may also wish to address issues related to the U.S. withdrawal from the proposed Trans-Pacific Partnership (TPP) free trade agreement among the United States, Canada, Mexico, and 9 other countries. Some observers contend that the withdrawal from TPP could damage U.S. competitiveness and economic leadership in the region, while others see the withdrawal as a way to prevent lower cost imports and potential job losses. Key provisions in TPP may also be addressed in 'modernizing' or renegotiating NAFTA, a more than two decade-old FTA. NAFTA was controversial when first proposed, mostly because it was the first FTA involving two wealthy, developed countries and a developing country. The political debate surrounding the agreement was divisive with proponents arguing that the agreement would help generate thousands of jobs and reduce income disparity in the region, while opponents warned that the agreement would cause huge job losses in the United States as companies moved production to Mexico to lower costs. In reality, NAFTA did not cause the huge job losses feared by the critics or the large economic gains predicted by supporters. The net overall effect of NAFTA on the U.S. economy appears to have been relatively modest, primarily because trade with Canada and Mexico accounts for a small percentage of U.S. GDP. However, there were worker and firm adjustment costs as the three countries adjusted to more open trade and investment. The rising number of bilateral and regional trade agreements throughout the world and the rising presence of China in Latin America could have implications for U.S. trade policy with its NAFTA partners. Some proponents of open and rules-based trade contend that maintaining NAFTA or deepening economic relations with Canada and Mexico will help promote a common trade agenda with shared values and generate economic growth. Some opponents argue that the agreement has caused worker displacement.