Isn't the USA older then pretty much every country in Europe? Maybe the UK could be considered older depending on how you count it and San Marino is there but all the other major ones like Germany, Italy, France, Spain, etc aren't even 100.

Sweden would like a word...

How in the world can you claim that France is not even 100? The German empire was established in 1857, which is definitely more than 100 years ago; it's also not unreasonable to say that the HRE could be equated to the German state, that Spain is the continuation of Castille, and that the Roman empire can be considered the direct precursor to Italy

There's a cultural through line for all these countries, often stretching back thousands of years, which means that they reach further back than the definition of the modern state

It's interesting how arrogant Europeans can be towards the U.S. when they themselves seeded the U.S.!

My Dad has a vacuum cleaner that is older than USA