Otis, Harrison Gray, 1765-1848, American political leader, b. Boston; nephew of James Otis. He practiced law in Boston, and was elected (1795) to the Massachusetts legislature. A staunch Federalist, he served (1797-1801) in Congress and was again a member of the state legislature from 1802 to 1817. In 1814 he was a leader of the Hartford Convention and subsequently defended that meeting. Otis was a U.S. Senator (1817-22) and mayor of Boston (1829-31). He published Letters Developing the Character and Views of the Hartford Convention (1820) and Otis' Letters in Defence of the Hartford Convention (1824).