Sloan was born in Princeton, New Jersey. He attended Hotchkiss and spent his last year of preparatory school at the Aldenham School in Elstree, Hertfordshire, England.[2] He graduated with a B.A. (Honors) from Princeton University in 1963, and then served in the United States Navy until 1965.
In 1965 he worked as a fund raiser for the Republican Congressional Campaign Committee, then for the Republican National Finance Committee until 1968.
In 1968 Sloan served as assistant finance director on the Nixon–Agnew Finance Committee, then after the election served as a personal aide to Nixon on the Presidential Transition Committee until early 1969, when he joined the White House Staff as an assistant to Dwight Chapin on January 20. Under direction of Chapin, Sloan supervised the mail operation in the appointments office, which included handling all invitations to the president. He was also responsible for staffing and planning White House social functions until early March 1971.[3]
That same year he married Deborah Murray and served as a finance/campaign expert for what was originally the Citizens Committee to Re-Elect the President, then headed by acting director Jeb Magruder, (who became deputy campaign director when John Mitchell resigned from the Justice Department to take up his political duties full-time in 1972). The organization was renamed the Committee for Re-Election of the President (CRP), with Sloan as its treasurer.[3]
Bob Woodward and Carl Bernstein said that Mark Felt told them that Sloan knew nothing about the Watergate burglary or how the money he disbursed was actually used. Sloan resigned when he found out what the White House Plumbers were up to and became a source for Woodward and Bernstein. Sloan was not identified by name in their Washington Post stories about the Watergate scandal[citation needed] but was in their book about their reporting of it, All the President's Men, in which he was portrayed as one of the few honest men they interviewed.
Sloan subsequently became a trustee of Princeton University. Since 1985 he has been a director of the Manulife Financial Corporation, a Canadian-based financial services group. From 1998 to 2008 he was deputy chairman of Woodbridge Foam, a supplier of urethane technologies to the automotive industry. Sloan is also a director of Wescast Industries, an automotive supplier whose stock trades on the Toronto Stock Exchange.
