 Lewis was one of the founders of the Mount Sinai Hospital, and served, since its organization in 1852, on its board of management as secretary, director, and vice-president, resigning the last-named office in 1873.He founded (1872) the School-Teachers' Life Assurance Society, and was in 1874 chairman of the relief association for the Ninth Ward.In 1851, the Ladies' Benevolent Society presented him with a gold medal in acknowledgment of the valuable aid he had rendered that body.