I think many of the people of the US and many other countries outside from Europe do not know enough about Europe. And what they are told by the media, is largely lie.
The Holy Roman Empire of German Nation didn’t last 500 years, as you said, but 1000 years - exactly from 843 (treaty of Verdun) to 1806 (during the Napoleonic wars). And b.t.w., Obe, Metternich was not Austrian but German, he was born in Koblenz; but that doesn’t matter very much because Austria had been a part of Germany until 1866 - and again from 1938 to 1945 as you probably know, for example: Hitler was an Austrian, he was born in Braunau (Inn). Since the end of the Second World War the Austrians have been confusing Metternich with Hitler and saying Metternich was an Austrian and Hitler a German, although the reverse is true.
There were more than one attempt in the European history to form an European Union, and any time it was Germany that did the first step. The EU we now have is a product of six countries: West-Germany, France, Italy, Holland, Belgium, Luxemburg.
What the German government started at that time was almost the same that Europe got later, after the two world wars, but it was just the beginnig of the First World War that destroyed this European Union, as if there were interests to prevent it (and such interests existed, especially in England).
The German Hanse or other Städtebünde (associations of cities in Germany and Italy) were the first attempts of creating something like an European Union.
The project of an European Union has always had proponents and opponents. The last powerful European opponent was the British Empire. No wonder that there was no possibility for an European Union before the British Empire ended. The German Empire was no European opponent but the most powerful proponent, and - of course - the most powerful rival of the British Empire. The profiteer of the rivalry between the British and the German Empire was the USA - that is the reason why the Dollar Empire could be formed. So the current most powerful European opponent is the USA as a Dollar Empire, and merely other than economic unions with the USA are no European opponents, for example the NATO. So the NATO is important also for Europe; but again: I don’t want such an aggressive NATO, and I also don’t want the hierarchical structure the NATO has. We should reform the NATO, change it from an aggressive and unilateral into a defending and multilateral military union.