We also have this from Pope Leo XIII:

“Nor, perchance did the fact which We now recall take place without some design of divine Providence. Precisely at the epoch when the American colonies, having, with Catholic aid, achieved liberty and independence, coalesced into a constitutional Republic the ecclesiastical hierarchy was happily established amongst you; and at the very time when the popular suffrage placed the great Washington at the helm of the Republic, the first bishop was set by apostolic authority over the American Church. The well-known friendship and familiar intercourse which subsisted between these two men seems to be an evidence that the United States ought to be conjoined in concord and amity with the Catholic Church. And not without cause; for without morality the State cannot endure-a truth which that illustrious citizen of yours, whom We have just mentioned, with a keenness of insight worthy of his genius and statesmanship perceived and proclaimed.”
http://the-american-catholic.com/2009/02/22/pope-leo-xiii-on-america-and-george-washington/

In the US, that pride is often most centered around specific expressions of American political and philosophical ideals such as the Declaration of Independence, Constitution, Gettysburg Address, etc.

In other countries, pride might to taken in analogous or different attributes: The English in their history and common law, the French in their aesthetic and intellectual heritage, the Polish in their religious and historical roots, etc.

I think on of the reasons Americans tend to take pride particularly in expressions of ideal such as the Declaration of Independence is that we do not in fact have much of a “national” identity in the way that most nation-states in the precise meaning of the term do. There is a history of “American” people and what they’ve done, and a shared language, but there is not a shared racial background or a culture in the fuller sense of the term, and many of our ancestors actually showed up here after much of the historical heritage of the country had actually taken place. Yet none of this serves to make people less American.

This is, I think, why documents and speeches play a larger than usual role in American national identity — and in that sense it underlines how odd it is to charge the US of being “nationalistic”, in that in many ways the US is not a “nation state” in the way that many other modern countries are. It would be like accusing a member of the Hapsburg Empire of being “nationalist”.