 The battles between Clark, Daly, and Heinze, and later between just Heinze and industrialist financiers William Rockefeller and Henry H. Rogers are a large chapter in Montana history.Eventually, a company known as Anaconda Copper emerged as a monopoly, expanding into the fourth largest company in the world by the late 1920s.While the cost of smelting the complex copper-bearing ore was high, after the American Civil War, investors like William Andrews Clark and Andrew Jackson Davis began to develop Butte's mines and erect mills to extract the silver and gold.