What positive did the ancient Chinese gain from the unification of the country into a single state?

Positive consequences of the unification of the country:

1) The constant internecine wars between the kingdoms ceased. So Qin Shi Huang was able to unite the country and end the bloody wars.

2) A large wall was built at the northern borders against the nomads of the Huns;

3) There has been a centralization of state governing bodies. Now one emperor ruled;

4) A single army was created, which to a large extent surpassed in power any army of a separate kingdom;

5) Laws were passed that were valid throughout China.