First off, thank you for your great response.
And yeah, I kinda get that "United States" is just a title, but in my native language (portuguese) we have a specific word for americans: "estadunidense", which basically means "person born in the USA"
I was just wondering if there was a similar word in english that could be used specifically to these people, just like we have in portuguese. But again, thanks for your answer.
Also, fun fact: Brazil was actually called "United States of Brazil" for a short period, and our flag looked like a copy of yours, but in yellow and green. But then our king (thankfully) decided to go just by "Brazil"
Yes, we used to be.
Source: I'm Brazilian