Silicon Valley may be minting billionaires today, but tech wealth doesn't touch the riches of the robber barons.
Vanderbilt got his start sailing barges across New York Harbor, and gradually expanded into steamships and railroads. One of his favorite business tactics was to undercut the competition so heavily that they would pay him to stay out of a given market.
He was rough around the edges -- swearing, chewing tobacco -- and never really fit in with New York high society.
His heirs did better, building great mansions along New York's Park Avenue and hob-knobbing with the city's elite. But they spent heavily, and by a 1973 family reunion, not one of the 120 Vanderbilt descendants present was a millionaire.