 The strikers held out until April 1914, but then gave up the strike.Calumet and Hecla employees were not again unionized until 1943, when the company signed an agreement with the CIO-affiliated International Union of Mine, Mill, and Smelter Workers.During the Great Depression, copper prices dropped, and as a result most copper mines in the Copper Country closed, including Calumet and Hecla.