Robert M. Winthrop was the grandson of Robert Charles Winthrop (1809-1894), of Boston. Robert Charles Winthrop, a descendant of Governor John Winthrop of Massachusetts, graduated from Harvard and studied law with Daniel Webster. He was a member of the U.S. House of Representatives, serving as its Speaker form 1847-1849, and later a U.S. Senator, filling out the unexpired term of Webster.
Bibliography
1948
Mayo, Lawrence Shaw. The Winthrop Family in America. Boston, 1948: 343-44, 405.