What did we celebrate on the 4th of July? An America that no longer exists.
Should this trouble the philosopher? Before he is a citizen, the philosopher is a "spectator of all time and existence" in a marvellous phrase that comes down to us from Plato's Republic (486a). The rise and fall of great nations is just more grist for the philosopher's mill. His true homeland is nothing so paltry as a particular nation, even one as exceptional as the USA, and his fate as a truth-seeker cannot be tied to its fate. Like the heavenly Jerusalem, the heavenly Athens is not bound to a geographical location.
And if the philosopher should also aspire to the heavenly Jerusalem, he is all the more freed from an excess of anxiety over the inevitable passing away of what must pass away.
St. Augustine had to endure the twilight of a civilization. In 410 Alaric and his barbarian horde of Goths sacked Rome. There followed the invasion of North Africa and the siege of Hippo where Augustine was bishop and where he died in 430 while the city was under assault. But the owl of Minerva spreads its wings at dusk, and as the curtain fell on Rome, Augustine's thoughts took flight, the result being The City of God.
Am I succumbing to an excess of Kulturpessimismus? Perhaps. We shall see.