Charles O. Rossotti is a businessman and former IRS Commissioner. From 1965 to 1969, Rossotti worked for Robert S. McNamara, becoming deputy assistant secretary of defense for systems analysis. In 1970, Rossotti and several Department of Defense colleagues co-founded American Management Systems, a technology and management consulting firm. Rossotti served as chief executive officer from the late 1980s to the mid-1990s. In 1997, Rossotti was named Commissioner of Internal Revenue where he served for five years. He detailed his experiences at the IRS in his book, Many Unhappy Returns: One Manʼs Quest to Turn Around the Most Unpopular Organization in America. He currently serves as a senior advisor with the Carlyle Group.