Howard Hughes-By far the most fascinating entrepreneur on the list.  When he set his mind to do something, he did it.  Granted, he had a good start in life from his father’s business, but he accomplished a great deal more with his entrepreneurial spirit.  Though it only flew once, The Spruce Goose, was probably his most noted endeavor (good or bad).  Add to that RKO, TWA, a Las Vegas empire, and his reclusiveness, and he’s surely one of the most interesting businessmen in American history.     He was an American business tycoon, investor, aviator, aerospace engineer, inventor, filmmaker and philanthropist. He was one of the wealthiest people in the world. When he died in 1976 he had a net worth of 1.5 billion; equivalent to 6.22 billion today. http://en.wikipedia.org/wiki/Howard_Hughes