He began working for the Phelps Dodge Corporation, and in 1864 was named a Partner in the firm.Beach, Frederick Converse and Rines, George Edwin. The Americana: A Universal Reference Library. New York: The Americana Co., 1911. Dodge and his cousin, Daniel Willis James, transformed the Phelps Dodge company from a placid and profitable import business into one of the world's largest and wealthiest mining corporations. The Phelps Dodge company had decided to enter the mining industry, and hired professor of chemistry James Douglas to make an inspection of mining claims in the Southwestern United States. Douglas suggested that the two men invest in the Detroit Copper Mining Company of Arizona, which owned a copper mining claim in Warren, Arizona.Cleland, Robert Glass. A History of Phelps Dodge: 1834–1950. New York: Alfred A. Knopf, 1952. In 1881, Phelps Dodge not only took a controlling interest in the Detroit Copper Mining Company but also purchased a minority interest in the adjoining Copper Queen Mine in Bisbee, Arizona.Whitten, David O.; Whitten, Bessie Emrick; and Sisaye, Seleshi. The Birth of Big Business in the United States, 1860–1914: Commercial, Extractive, and Industrial Enterprise. Westport, Conn.: Greenwood Publishing Group, 2005. After the Copper Queen and Detroit Copper both struck the Atlanta lode"Phelps Dodge Corporation." In International Directory of Company Histories. Vol. 75. Jay P. Pederson, ed. Florence, Ky.: St. James Press, 2006. in 1884, Phelps Dodge bought out the remaining interest in the Copper Queen. The company merged its various mining interests into the Copper Queen Consolidated Mining Company in 1885, and installed Douglas as president and part-owner.
