The EU didn't exist in the nineteenth century.
Are you sure?
Yes. The EU began in 1993 with the ratification of the Maastricht Treaty.
It was formed from countries of its predecessor, the EEC, which was formed by the Treaty of Rome in 1957.
Before that, the two most powerful EU states, France and Germany (and most of the others) were at war from 1939-45, and before that, they (or their predecessors) were at War from 1914-18 (with Russia allied with France against Germany on both occasions).
To suggest that the EU, or the mere concept of a European Union, predates 1945 would be an utterly batshit nutso rejection of reality; To suggest that the nations of Europe were intransigently opposed to Russia through the century following the end of the Crimean War would be equally counterfactual to the point of drooling insanity.
it certainly looked like Countries of Europe were United in their conspiracy against Russia at that time.
At what time? The 19th century included periods of conflict and of alliance between many of the European Powers. There was no unity between the Powers at any point; occasional treaties allied two or three together against the others, but the idea that "Countries of Europe" in the C19th were
united against anyone is absurd.
Don't they teach
any history in Russia?
Seriously? The guy who thinks Europe was "United in their conspiracy against Russia" in the C19th is accusing someone else of being 'dense'?? Have you no shame at all?