Mr. Duncan attended WMU in the late 1940s and began his career in 1950 at what is now First of America-Michigan. In 1952, he designed the bank's first credit card, the oldest such operation in the United States.
He became the bank's president and CEO in 1969 and its chairman in 1976. He was also named president and CEO, and later chairman, of First of America Bank Corporation, Michigan's first multi-bank holding company.
He served on the boards of numerous organizations including the WMU Foundation.