When eleven-year-old Cornelius Vanderbilt began to work on his father’s small boat ferrying supplies in New York Harbor at the beginning of the nineteenth century, no one could have imagined that one day he would, through ruthlessness, cunning, and a pathological desire for money, build two empires—one in shipping and another in railroads—that would make him the richest man in America. His staggering fortune was fought over by his heirs after...