 The company experienced rapid growth due to a surge in demand for copper especially in Germany which then consumed 1/3rd of U.S. exports.Under Langeloth, AMCO expanded into production, opening refining plants for lead and copper.Prior to World War I, AMCO made a minority investment in Climax Molybdenum Company, the world's largest producer of molybdenum named after the Climax mine; the investment paid off due to increased demand from the war.