Only in America?  Under 35; living in America only a few years, they made it on their own. The multi—billionaires Sergey Brin and Larry Page created something of enormous value to others. 

Ethel C. Fenig  10 24 04

Thomas Lifson adds:

Not only in America, but mostly so. For example, Masayoshi Son of Japan, albeit of Korean heritage, became a multi—billionaire in his thirties. Even better, he studied at UC Berkeley, returned home, and showed other Japanese young people that entrepreneurship can pay off big—time.

America is a wonderful place, but capitalism and the rule of law are the necessary ingredients. Other countries can and do practice the same model, although their success rates are a bit lower.