to Atlanta and the following year became Coca-Cola's president. During his tenure from 1971 to 1974, the company enjoyed extensive growth. It also modernized its advertising. During this period Duncan bought the TE Ranch, southwest of Cody, Wyoming—a working cattle ranch established in 1895 by William F. "Buffalo Bill" Cody, from Coca-Cola's R. W. Woodruff. In 1974, Duncan left Coca-Cola to head back to Houston, where he became the chairman of both Rotan Mosle Financial Corp. and Robertson Distribution Systems. Carter administration Charles Kirbo, an advisor to Jimmy Carter, recommended Duncan to Carter for a position in his presidential administration. Carter nominated Duncan to be the Deputy Secretary of Defense. In the role, Duncan advocated to U.S. Congress to end the prohibition of women in combat. The Iranian Revolution occurred during his tenure, encompassing political changes that marked that nation's transformation from a monarchy under the pro-western Shah Mohammed Mohammad Reza Pahlavi to a so-called republic under the Ayatollah Ruhollah Khomeini. Duncan's duties involved multiple trips to several countries, including Iran, some of which were undergoing considerable turmoil. Duncan's military advisor was a young colonel named Colin Powell, who considered Duncan a mentor and good friend. In July 1979, President Carter nominated Duncan to succeed James Schlesinger as Secretary of Energy. The appointment drew some criticism, as Duncan had little experience in the oil business, but he developed the reputation of a strong manager. The experience strengthened Duncan's belief in conservation measures of all kinds, in addition to enhancing production. Duncan imposed quotas on oil imports, encouraged weatherization of homes, and obtained subsidies for gasohol, helping to mitigate the worst impacts of the energy shortage. Corporate and state service Leaving Washington DC at the end of Carter's term, Charles Duncan again returned to Houston, in January 1981. There he founded—with his brother, John H. Duncan—Gulf Partners, a private investment firm. He also served on the boards of The Coca-Cola Company, J. P. Morgan Chase, Texas Eastern, American Express, United Technologies, and more. Duncan also served as Limited Partner of Houston NFL Holdings, LP and as treasurer and director of The Methodist Hospital. Additionally, he was a director of The Welch Foundation until October 2004. At the request of Texas Governor Mark White and billionaire politician Ross Perot, Duncan joined the Select Committee on Public Education, and the Texas State Board of Education. The board formulated the controversial "no pass no