His political service includes mayor of Savannah, Georgia (1778), sheriff of Chatham County, Georgia, member of the Georgia House of Representatives, state Treasurer, and revolutionary governor of Georgia from 1782 to 1783. Martin took the office of governor on January 2, 1782 from Sir James Wright, who said, "The rebel Governor Martin, now at Ebenezer, has issued three proclamations, one to the King’s troops, one to the Hessians, and another to the militia, inviting them all to revolt and join the virtuous Americans against the tyranny of the British government." Wright also referred to Martin as "Black Jack from the Northward."