Upon returning home, Dixon attended and graduated from Harvard Business School and began what was to be a long and distinguished career in the private sector. He worked first for Brown Brothers Harriman in Boston, Massachusetts, then for Davis and Davis, a stock broker in Providence, Rhode Island, and then for Sperry and Hutchinson, the New York City creators of S&H Green Stamps.
While in Providence, Dixon met Marjorie "Peggy" Ellen Freeman (granddaughter of the prominent engineer John Ripley Freeman), whom he would later marry. They had three children; identical twin boys George Elliott Dixon and Andrew Taft Dixon, and a daughter, Candis Hall Dixon.
Meanwhile, Dixon was making a name for himself in the business world, and First National Bank of Minneapolis, taking notice, recruited him to serve as president in the mid-1960s. Dixon accepted and held the position until 1974, at which point Gerald Ford became the 38th President of the United States of America. Ford asked Dixon to serve as his Deputy Secretary of the Treasury, working with Treasury Secretary William E. Simon to manage financial policy, along with the Secret Service, ATF, and the Customs Service. While serving as the Deputy Secretary, Dixon often attended cabinet meetings that included such political figures as Secretary of Defense Donald Rumsfeld and Secretary of State Henry Kissinger.
When Ford's term ended, Dixon returned to Minneapolis to assume the role of chairman and president of First Bank System. While in Minnesota, Dixon became involved with Carleton College, a small liberal arts college in nearby Northfield, Minnesota. He served on the college's board of trustees, including a term as chairman in the 1990s. While chairman, Dixon recruited Stephen R. Lewis to take the post of president of the college. In 2000, Carleton awarded Dixon a PhD for Lifetime achievement.