| 1955 | The American Adam: Innocence, Tragedy, and Tradition in the Nineteenth Century. Lewis's first major critical work is an influential intellectual and literary study of nineteenth-century America, which traces the Edenic myth in the works of American writers. Lewis would win the Pulitzer Prize for Edith Wharton: A Biography (1975). |
| 1975 | Edith Wharton. Lewis wins the Bancroft Prize, the National Book Critics Circle Award, and the Pulitzer Prize for this biography, which uncovers new material on the writer and challenges conventional views of Wharton as genteel. Mark Royden Winchell declares the book "one of the very best we have on an American writer." |