I think that from all of the countries in the world, the US Independence day is the most recognizable one. I mean, come one, does anyone who is not from Brazil know the importance of September 7th? No one goes around saying Happy 7th of September, we just don't do it. Why is that? My opinion is that Americans are great at Marketing :-) On top of that, they are proud of who they are, (some) Brazilians on the other hand... not so much... Americans are very patriotic and they believe in their country, Brazilians are not and do not believe in their country, but enough about Brazil, this is about the USA.
After living here on and off for so many years, loving and hating being here, I've come to believe that the reason for all that pride is that, like it or not, this is a country where you can make something of your life. By no means I am saying that it's easy, it's not! And anyone who tells you the opposite is lying. It's hard and there are people who work so hard all their lives and stagnate. Others give up, others follow the wrong path, but in general, you can have a stable life and meet your basic needs (food, shelter...).
This is a country where you fight for your rights and actually get somewhere. Other countries you fight, fight, fight and it all is forgotten about it after a week, nothing resolves, because the government doesn't listen. In the US, like it or not, agree with its ideals or not, people do have a say, they will be heard and things will be resolved. It might take years, but it's the only place that I've lived in where the voice of the people is heard.
Is it the perfect place? No! Does it have its problems, heck yes! But at this point in my life is the place where we chose to be until we decide to move on.