- Samuel Langhorne Clemens, better known by the pen name Mark Twain, was an American author and humorist. Twain is most noted for his novels Adventures of Huckleberry Finn, which has since been called the Great American Novel, and The Adventures of Tom Sawyer. He is extensively quoted. During his lifetime, Twain became a friend to presidents, artists, industrialists, and European royalty. Twain enjoyed immense public popularity. His keen wit and incisive satire earned him praise from both critics and peers. William Faulkner called Twain "the father of American literature".