[blacksmythe]

Within one lifetime, probably so. The next generations might add more money, or spend it all.

There is an old proverb "from shirtsleeves to shirtsleeves in 3 generations". (http://answers.yahoo.com/question/index?qid=20080114145024AA...)

[blacksmythe]

In some cases this can take longer:

"Six Waltons Have More Wealth Than the Bottom 30% of Americans" (http://finance.yahoo.com/news/six-waltons-more-wealth-bottom...)