Mason, born in Virginia in 1811, came to Michigan with his father, who was appointed territorial secretary in 1830. Mason succeeded his father as secretary in 1831. When the territorial governor died in 1834, Mason became acting governor. In this new role, Mason led the territory into the two-year struggle to become a state. 

Although Michigan did not become a state until January 26, 1837, Mason had been elected the first state governor in October 1835. He was re-elected in 1837, but did not seek a third term because of controversy surrounding the state’s $5 million loan for internal improvements. Mason moved to New York City after leaving office. He married and fathered three children. On January 1, 1843, he became sick, dying three days later. He is buried in Detroit.