You can see that the number one tag is united-states: a whopping 465 questions. This is a problem. There are 4235 questions on the site, and over 10% of them are about one country, despite the fact that this country comprises less than one-twentieth of the world's population, and its written history only goes back to the fifteenth century, that is if you count the three hundred years before it became an independent country (the history of what is now the USA before the Europeans' arrival is, of course, on a different tag).
Contrariwise China only has 116 tags. China's written history goes back four thousand years, and it's currently home to over one billion people: more than one seventh of the human population. How can it possibly be right that it has fewer questions than the USA?
I don't say this to disparage the USA or American contributors, nor am I saying we need fewer questions about the USA. I have asked a number of questions about the USA myself, and will continue to do so.
However, it is reasonable that the number of questions asked on a topic should reflect the quantity of information available about that topic. Stack Exchange is an American company, and I admit that I didn't read Stack Exchange's terms and conditions when I joined, but I'm willing to bet that American exceptionalism is not something I signed up to.
Unfortunately, the problem is not confined to the USA as a topic. World War 2 gets more tags than the whole of the century in which it is contained, and more than the two continents in which most of it took place. Nazi Germany, a twelve year period, gets more tags than plain old Germany, a country which has existed in some form since the Roman Empire. And yes, I have asked questions about all those things, and I don't want anyone to ask fewer questions about them, either.