It is actually an amazing account of the life and time of John D Rockefeller and his close family. The deals done and the plans laid meant that he became the richest man every to have walked the earth - being worth (in modern money) the combined worth of Bill Gates, Warren Buffett and Mr WalMart three times over.
The book itself explains about his methods in business and how the combination of his intellect, planning and attention to detail lead to his immense wealth.