One became America's greatest writer. The other died in obscurity and failure. As brothers, they shaped each other's lives and work. In a compelling way, Philip Fanning traces the fraternal relationship of Orion and Samuel Clemens from its beginning in Hannibal, Missouri, in the 1830s to Orion's death in Iowa in 1897. He demonstrates that Orion's influence on the writer known as Mark Twain was profound, pervasive, and prolonged.