 Under Agassiz's management, the Calumet and Hecla mines rapidly increased production, and by 1870 were producing over half of the United States' copper.In 1871, the Calumet and Hecla Mining Companies were consolidated, along with the Scott and Portland Mining Companies, to form the Calumet and Hecla Mining Company.Agassiz was the president of the newly incorporated company, a position he held until his death in 1910.