Mark Twain Mark Twain Mark Twain (November 30, 1835 – April 21, 1910), real name Samuel Langhorne Clemens, was an American writer, humorist, entrepreneur, publisher, and lecturer. Among his novels are "The Adventures of Tom Sawyer" (1876) and its sequel, the "Adventures of Huckleberry Finn" (1885), the latter often called "The Great American Novel". Twain was raised in Hannibal, Missouri, which later provided the setting for "Tom Sawyer" and "Huckleberry Finn". He served an apprenticeship with a printer and then worked as a typesetter, contributing articles to the newspaper of his older brother Orion Clemens. He later became a riverboat pilot on
Mark Twain Cave and stalactites in large open areas. Mark Twain Cave and Cameron Cave instead have a multitude of narrow, winding passages. The caves are made mostly of a soft limestone called Louisiana Lithographic Limestone and found only in a area around Hannibal and Louisiana, Missouri. The limestone has been estimated by geologists as around 350 million years old, while the cave passages were formed some 100 million years ago. Mark Twain Cave covers some consisting of four entrances and 260 passages, maintaining a year around temperature of . While it is possible that prehistoric Native Americans were aware of the cave,