That's all well and good.
Just remember that Europe the area. (The union is different, those things can change, because of people that leave or enter the union, and also American countries that could theoretically leave USA like for example Texas) so let's just compare areas, not unions.
Europe the area is larger than USA. And that's even with Alaska and Hawaii, and withouth Greenland.
Also whenever Americans talk about size, they allways show the map of the contiguous United States only, but always include the area of Alaska and Hawaii.
Which is kind of unfair if Greenland and other areas are not included, which are not contiguous.
USA has roughly 200 million less people, and less water and more area in one big mass instead of spread.
One language, one currency, and so it cam maybe feel like it's larger. But it's really not.
My source. Google. Simple as that. You just have to know how to read the numbers.