In 1918, Forbes Magazine published a list of the 30 richest Americans.  At the top was oil tycoon John D. Rockefeller, Sr, whose wealth was estimated at a whopping $1.2 billion — more than 5 times as much as his closest rival for the title of richest American, Henry Frick.   But by that time, Senior had already started giving much of his vast fortune  to charity; by the time he died in 1937, he had given away a total of precisely $530,853,632.

He also had passed along $470 million to his son John D. Rockefeller, Jr --  forty times what he gave to either of his surviving daughters --  because he trusted  his son to give most of that away, too, which  Junior proceeded to do, giving away around $500 million before he died in 1960, while still passing on around $160 million to his own six children.