Final answer:
NAFTA was strongly opposed by organized labor due to fears of job losses and offshoring of jobs to Mexico. It was ratified in 1993 after additional agreements to protect workers and the environment were included.
Step-by-step explanation:
When the North American Free Trade Act (NAFTA) was passed, it was strongly opposed by organized labor. NAFTA was established in 1993 to eliminate trade barriers between the United States, Canada, and Mexico. While it aimed at fostering free trade and economic growth by creating the world's largest trading bloc, it also raised concerns about job losses in the United States, especially among industrial workers.
American labor unions feared that cheaper labor markets in Mexico would result in the offshoring of jobs. Despite opposition, the treaty was ratified by Congress in late 1993, with additional agreements to protect workers and the environment.