Enacted on January 1, 1994, the North American Free Trade Agreement (NAFTA) created a trilateral trade bloc amongst the United States, Canada, and Mexico that eliminated barriers to trade and investment. Proponents of NAFTA claimed it would stimulate the Mexican economy and, therefore, curb undocumented immigration from Mexico to the United States. However, U.S. agricultural imports in Mexico pummeled the prices of many Mexican products, forcing many agricultural workers to migrate for work. Moreover, U.S. manufacturers built a major industrial zone on the southern side of the border to take advantage of weak labor, environmental, and worker safety regulations in Mexico, contributing to increased border populations. NAFTA not only compelled many Mexicans to migrate north, it also led to depressed wages and job losses among American blue-collar workers. Both realities fueled a tide of anti-immigrant sentiment in the United States.