Mark Twain, American novelist, humorist, and critic (born 1835)

Samuel Langhorne Clemens, known by the pen name Mark Twain, was an American writer, humorist, and essayist. He was praised as the "greatest humorist the United States has produced", with William Faulkner calling him "the father of American literature". Twain's novels include The Adventures of Tom Sawyer (1876) and its sequel, Adventures of Huckleberry Finn (1884), with the latter often called the "Great American Novel". He also wrote A Connecticut Yankee in King Arthur's Court (1889) and Pudd'nhead Wilson (1894) and cowrote The Gilded Age: A Tale of Today (1873) with Charles Dudley Warner. The novelist Ernest Hemingway claimed that "All modern American literature comes from one book by Mark Twain called Huckleberry Finn."

April 21 is the 111th day of the year in the Gregorian calendar; 254 days remain until the end of the year.