St Patrick's day is probably bigger in Boston than in Ireland.
Halloween is an old English event.
Cinco de Mayo? Spanish/south American.
When you consider that America really only has dates of wars to celebrate due to a lack of history compared to Europe, I guess they have to adopt the ones used by the countries from which their ancestors came from. (Sorry yanks, I couldn't help but twist the knife.
)
It's funny to see July 4th being bandied about by the media over here in the UK now.
We're also starting to get in on the more ethnic ceebrations in the UK now too. Diwali and other Asian celebrations. Notting hill carnival is very Carribean in origin.