Winsor, Justin (1831-1897), was an American historian and librarian. His first ambition was to be an author, and he wrote many books and articles. Winsor became interested in libraries after his appointment in 1866 as a Boston Public Library trustee. He became librarian at the Boston Public Library in 1868, and at Harvard College in 1877. Winsor promoted the development of libraries throughout the country, and served as first president of the American Library Association. He was born in Boston. He edited the eight-volume Narrative and Critical History of America.