NAFTA (North American Free Trade Agreement) is an agreement among the United States, Canada, and Mexico to

Question:

NAFTA (North American Free Trade Agreement) is an agreement among the United States, Canada, and Mexico to reduce trade barriers and promote the free flow of goods and services across borders. Many U.S. labor groups were opposed to NAFTA.
Can you explain why? Can you predict how NAFTA might alter the goods and services produced in the participating countries?