Because they were driven away from their homelands by force
The earliest Chinese people did not have to worry about invasions from foreign countries because of their strong army and geography. The Chinese army present in ancient times were very strong and able to defend their lands. Chinese also build china wall in order to protect their lands from the invasion of other people. The geography of china also made difficult for the invaders to capture china.
It was a result of the cooperation between the public and the private sector. The private sector owners built things like railroads and public roads so they wanted to get money back through tolls and turnpikes. In return, they would pay taxes for money obtained this way and the states enjoyed this money and wasn't bothered by what was happening.
