 From 1868 through 1886, it was the leading copper producer in the United States, and from 1869 through 1876, the leading copper producer in the world.From 1871 through 1880, Calumet and Hecla turned out more than half the copper produced in the United States.In each year save one between 1870 and 1901, Calumet and Hecla made most of the copper produced in the Michigan copper district.