A key figure in the American labor rights movement in the 1930s was John L. Lewis, who served as the president of the United Mine Workers of America. He was instrumental in forming the Congress of Industrial Organizations (CIO), advocating for the rights of industrial workers. Lewis championed the cause of labor unions, pushing for better working conditions, fair wages, and the right to organize. His efforts significantly shaped labor relations in the United States and established collective bargaining as a critical tool for workers' rights during that era.