We have festivals. You might argue about cultural significance of course, but we have festivals. Chinese New Year, cherry blossom festivals (there's one in Washington DC every year). I'd say probably that food festivals are what defines American culture. We are passionate about the food we eat. Just about everything has a festival somewhere. Around where I live there is a pretty big cherry festival, because Michigan is the largest producer of that fruit in this country.And I am quite sure every country, except USA, has traditions like this one.
We also have customs, though Christian ones tend to dominate now. That's not how it was in the beginning.
But then America is a country that built itself around being open to and absorbing culture, so it really depends who you are and what you came here for. I won't deny that culture fascinates me, but I'm happy that it doesn't dominate here. That in my opinion encourages astounding prejudice.