Mark Twain three of his siblings survived childhood: Orion (1825–1897), Henry (1838–1858), and Pamela (1827–1904). His sister Margaret (1830–1839) died when Twain was three, and his brother Benjamin (1832–1842) died three years later. His brother Pleasant Hannibal (1828) died at three weeks of age. When he was four, Twain's family moved to Hannibal, Missouri, a port town on the Mississippi River that inspired the fictional town of St. Petersburg in "The Adventures of Tom Sawyer" and the "Adventures of Huckleberry Finn". Slavery was legal in Missouri at the time, and it became a theme in these writings. His father was an attorney
Mark Twain Cave Cave is open from Memorial Day through Labor Day only. Mark Twain Cave Mark Twain Cave — originally McDowell's Cave — is a show cave located near Hannibal, Missouri, U.S.. It is the oldest operating show cave in the state, giving tours continuously since 1886. Along with nearby Cameron Cave, it became a registered National Natural Landmark in 1972, with a citation reading "Exceptionally good examples of the maze type of cavern development". The cave — as "McDougal's Cave" — plays an important role in the novel "The Adventures of Tom Sawyer" (1876) by Mark Twain and was renamed in