Who was Mark Twain? Not a real person. Mark Twain was the name Samuel Clemens picked for himself for his writing and speaking career. It was a term used by steamboat men on the Mississippi River. Little did Sam Clemens guess that this pseudonym he’d chosen, his false name, would soon seem to have a life all its own. Soon very few people remembered that he was really Sam Clemens and thought only of Mark Twain, a wonderfully funny speaker and terrific writer. He became the talk of America, and everyone, even today, over a hundred years later, can recognize him by his white suit and mustache. But who was the real man? What was he like? The story of Sam Clemens is an amazing one, tied into the growth of the United States itself.