Today the Rockefellers as a collective own as much as 10 billion. Thats is a large chunk of money, but John D Rockefeller's net worth was valued at 336 billion adjusted for inflation. Now typically wealth creates more wealth. So how did this historical figure go from being so ungodly rich with the most powerful company in the world to having his entire family valued at 10 billion between 200 people?
This is a complicated question because when people see that the brothers had such a large sum they automatically assume the same thing you did. That wealth typically creates more wealth. The trouble is no one takes into account the time value of money. Which states that money today is more valuable than money tomorrow or a year from now. He was once valued at 336 billion but that was for at that time in history. The value of money decreases over time, plus the brothers were worth that much. Since their deaths it has been split between 200 family members. The fact that they are still able to be wealthy at this day and age is more what we're use to. In that families that are wealthy usually remain wealthy. The Rockefellers actually made some smart investments. They owned Chase Manhattan bank and were large investors in Apple, so their wealth has accrued but the world will never see the same as in the Gilded age. When there was The Rockefellers, JP. Morgan, Carnegie and So on.
Estate and death taxes removed some of the wealth. Splitting it between 200 people who each have their own households and expenses did away with more of the money.