After passage of the National Recovery Act in 1933 during the Great Depression, organizers spread throughout the United States to organize all coal miners into labor unions. Under the powerful leadership of John L. Lewis, the UMW broke with the American Federation of Labor and set up its own federation, the CIO (Congress of Industrial Organizations). Its organizers fanned out to organize major industries, including automobiles, steel, electrical equipment, rubber, paint and chemical, and fought a series of battles with the AFL. The UMW grew to 800,000 members and was an element in the New Deal Coalition supporting Democratic President Franklin D. Roosevelt. Lewis broke with Roosevelt in 1940 and left the CIO, leaving the UMW increasingly isolated in the labor movement. During World War II the UMW was involved in a series of major strikes and threatened walkouts that angered public opinion and energized pro-business opponents. After the war, the UMW concentrated on gaining large increases in wages, medical services and retirement benefits for its shrinking membership, which was contending with changes in technology and declining mines in the East.