Mark Twain was the pen name of Samuel Langhorne Clemens (1835-1910), an American writer who grew up beside the Mississippi and worked as a riverboat pilot before turning to journalism. The river furnished the material for his best-known books, The Adventures of Tom Sawyer (1876) and Adventures of Huckleberry Finn (1884), which brought American vernacular speech into serious fiction. His later work grew markedly darker, turning to satire on imperialism, religion and what he called the damned human race.