> Note that institutions are shorter lived than one might think. If you have become 25 this year, you'll have lived for more than 10% of the US's entire lifetime. 75, and you'll have lived for a third of its existence.

Note also that the US has one of the longest lived current governments in the world. There are plenty of countries that have been around longer, but most of them have forms of government that came into effect there later than when the US got its current form of government.