Daly, Marcus, 1841–1900, American copper magnate, b. Ireland. He went to New York City at 15 and later moved to California, where he worked as a miner. He was employed by the "silver kings," J. G. Fair and J. W. Mackay, at the Comstock Lode. In 1876 he was sent by a large company to investigate the silver mines at Butte, Mont. Discovering that there was rich copper beneath the silver, he purchased the Anaconda silver mine and tested the copper. Then, with the backing of George Hearst and others, he quietly bought up neighboring mines and formed a mining company. He built a smelter at Anaconda and connected it by rail with Butte. He was so successful that Anaconda became almost a household word in the United States. Daly purchased coal mines to fuel his furnaces, bought forests to supply his timber, and built power plants to supply the mines. He also established a number of banks. His great rival was William A. Clark, and their bitter struggle for control kept the copper industry in turmoil; the contest for power included other men, notably F. Augustus Heinze. Though Daly himself did not seek public office, his effective political machine thwarted Clark's ambitions for many years. The feud dominated Montana politics and economy. Daly also established a newspaper, the influential Anaconda Standard.
See C. G. Glasscock, The War of the Copper Kings (1935, repr. 1971).