The Calumet and Hecla Mining Company extracted copper from the rich Calumet conglomerate from 1866 to 1968. As early as 1870, it produced over half of Michigan's copper, and Michigan accounted for 87% of the copper mined in America. Between 1880 and 1900 alone, the Boston-based company produced dividends of $57 million. Its immense profits came from a work force composed mostly of immigrant laborers, an impressive array of steam-powered technology, and the good fortune of a copper-rich ore body. By 1898, the company owned some 1,000 dwellings as well as a nearly equal number of employee-built houses on company land, and many paternalistic benefits attracted and retained laborers and their families. By the late 1890s, about 50 steam engines powered machinery at the mine site, and in 1899 the Michigan Commissioner of Mineral Statistics said their power equaled that generated by the great electric plant at Niagara Falls and about the power used by an average manufacturing city of 200,000 people. From 1919 to its closure in 1968, the company's decline appeared in gradually diminishing copper production, dividends, and employment. Its formidable corporate and industrial buildings from its greatest prosperity between 1866 and 1919 remain as evidence of more than a century of hard rock mining.