Born in Cambridge, Massachusetts, the son of Kathleen and William Francis Regan, he was of Irish Catholic origins. Regan earned his Bachelor of Arts in English from Harvard College in 1940 and attended Harvard Law School before dropping out to join the Marine Corps at the outset of World War II. He reached the rank of lieutenant colonel while he was serving in the Pacific Theater. He was involved in five major campaigns, including Guadalcanal and Okinawa. In 1942, Regan married the former Ann George Buchanan with whom he had four children: Donna Regan Lefeve, Donald T. Regan, Jr., Richard William Regan, and Diane Regan Doniger.
Wall Street
After the war, he joined Merrill Lynch & Co., Inc. in 1946 as an account executive trainee. He worked up through the ranks, eventually taking over as Merrill Lynch's chairman and CEO in 1971, the year the company went public. He held those positions until 1980. Regan was one of the original directors of the Securities Investor Protection Corporation and was vice chairman of the New York Stock Exchange from 1973 to 1975. He was a major proponent of brokerage firms going public, which he viewed as an important step in the modernization of Wall Street. Under his supervision, Merrill Lynch had its initial public offering on June 23, 1971, becoming only the second Wall Street firm to go public. During his tenure in these two positions, Regan pushed hard for an end to minimum fixed commissions for brokers, which were fees that brokerage companies had to charge clients for every transaction they made on the clients' behalf. Regan saw them as a cartel-like restriction. His lobbying played a large part of fixed commissions being abolished in 1975.
Reagan administration
President Ronald Reagan selected Donald Regan in 1981 to serve as Treasury Secretary, marking him as a spokesman for his economic policies, dubbed "Reaganomics". He helped engineer changes in the tax code, reduce income tax rates, and decrease taxes for corporations. Regan unexpectedly swapped jobs with then White House Chief of StaffJames Baker in 1985. As chief of staff, Regan was closely involved in the day-to-day management of White House policy, which led Howard Baker, Regan's successor as chief of staff, to give a rebuke that Regan was becoming a "prime minister" inside an increasingly-complex Imperial Presidency. During his four years as Secretary of the Treasury, Regan did not have a single one-to-one meeting with the president. Regan was forced to resign for repeatedly disagreeing with the First Lady and for being unable to contain the continuing political damage to President Reagan from the Iran–Contra affair. Regan's 1988 memoir, For the Record: From Wall Street to Washington, exposes his disagreements with First Lady Nancy Reagan, revealing publicly that she had a personal astrologer who was later revealed to be Joan Quigley with whom she consulted and who helped steer the president's decisions. Regan wrote:
Virtually every major move and decision the Reagans made during my time as White House Chief of Staff was cleared in advance with a woman in San Francisco who drew up horoscopes to make certain that the planets were in a favorable alignment for the enterprise.
"And the horse you rode in on" was a favorite saying of Regan. He learned it from a poker buddy in Texas who said "fuck you and the horse you rode in on." Regan adopted the latter part of the phrase. In the portrait of Regan that hangs on the third floor of the treasury, the title of a book in the background reads And the Horse You Rode In On. "You've got to give loyalty down if you want loyalty up." "You're gonna have to speed it up", or simply "Speed it up", was a phrase that Regan infamously said to President Reagan during one of his speeches, effectively ordering him to hurry up, as shown in Michael Moore's documentary, .
Retirement
Regan retired quietly in Virginia with Ann Regan, his wife of over 60 years. In late life, he spent nearly 10 hours a day in his art studio painting landscapes. He had four children and nine grandchildren.
