After the end of a no-strike pledge agreed to by unions during World War II, the nation witnessed the greatest wave strikes in American history. On April 1, 1946, 400,000 bituminous coal miners–more than 75,000 of them in Pennsylvania–went out on strike for better wages, health benefits, and safety regulations. When United Mine Workers leader John L. Lewis refused to end the strike in May, President Harry S. Truman seized the mines and ordered the strikers back to work. Defying the president, most stayed out until December, when the coal companies agreed to the bulk of Lewis's demands.
