He was born in New York City and claimed Scottish descent. He moved to Savannah, Georgia with his family, when he was a kid. He was married to Frances Raven Grimball, served in the U.S. Navy from 1941 to 1952 and was promoted to the rank of Lieutenant Commander and was an attorney.
Maclean succeeded Dr. Ellison Cook as a Council member in 1957 and became Mayor Pro Tem in 1958.
After the resignation of incumbent Mayor Lee Mingledorff, Jr. who decided to run for a seat on the Chatham County Commission in 1960, Maclean was selected by his peers to take over the Chief Executive's job. He then served the remainder of Mingledorff's term, which expired in 1962.
Maclean won re-election in 1962. He continued Mingledorff's local programs of public road improvements.
In 1966, Maclean suffered a White backlash. White people, especially segregationist considered him to be soft on racial issues. Savannah voters, who had given Republican presidential candidate Barry Goldwater a majority in 1964, defeated Maclean and his slate. Republican businessman Julius Curtis Lewis, Jr. succeeded Maclean as Mayor.