America retreated further into isolation.
Hoped I helped a bit!
The Yellow River region. The civilization of ancient China first developed in the Yellow River region of northern China, in the 3rd and 2nd millennia BCE. A large part of this area is covered by loess soil. In Chinese history, the Yellow River is not just a river; it stands for the origins of culture and civilization. ... That is because the Yellow River was the birthplace of ancient Chinese civilizations in the Xia (2100–1600 BC) and Shang (1600–1046 BC) eras — the most prosperous region in early Chinese history.
I hope this helps! ^^
It got much bigger and the air quality got better.
