China is the third-largest country in the world by area, ahead of even the United States. And everybody knows that it has the largest population and quite an extensive history behind it. I get all that so far.
What I don't get is how this idea that all of China's population is concentrated only in a few large cities... doesn't appear to be true. There are massive megalopolises everywhere throughout the country:
https://en.wikipedia.org/wiki/List_of_cities_in_China_by_population_and_built-up_area
According to that article, there are fifteen cities in China that have an urban population over eight million. That's the population of New York City. I have a hard time wrapping my head around the idea of eight million people living in a city in my country, let alone fifteen such cities.
In the United States, the largest cities' populations drop off pretty quickly. Not long after NYC, you start seeing cities like Philadelphia and San Antonio, which are not particularly significant. But in China, you can go a bit down the list and run into cities like Wuhan, Suzhou, and Shenyang.
These are all NYC-sized cities, but unheard of on a global scale. China is the only country in the world with so many of them. Especially if you take the one-child policy into consideration, how did China end up with 102 cities with over 1 million people while the United States only has ten?
One thing to keep in mind is that administrative boundaries work differently in China than in the United States. Municipal administrative units usually include most of the suburbs of a city, and some of the outlying rural areas as well. The most extreme example of this is Chongqing which is the size of South Carolina in order to put the Three Gorges Dam into the Chongqing urban area. However, even other Chinese municipal areas are much larger than their American counterparts.
In fact, the Chinese government is actively trying to keep it's cities small. Engels had strong views about vast urban agglomeration, and much of Chinese policies, from it's investments in intercity high speed rail, and the operation of the household registration system is designed to keep cities from getting too big. The success in this is mixed at best.