Sinclair Lewis was an American novelist who wrote several novels in the early 20th century. His most famous works include 'Arrowsmith' (10 letters), 'Babbitt' (7 letters), 'Dodsworth' (9 letters), 'Mainstreet' (10 letters), and 'Elmer Gantry' (11 letters). These novels are considered to be some of the most influential works of American literature and have been adapted into films, television shows, and plays.