What is Qin Shihuang's main contribution to history?

Qin Shihuang made many unprecedented achievements in unifying China, and listed several influential ones as follows:

1. Unified writing, making it the foundation of a nation and continuing to this day;

2. Abandoning state-owned counties became the standard management mode after the unification of China, which lasted for thousands of years;

3. Unifying currency and weights and measures greatly facilitates domestic commercial exchanges.

4. The cars are on the same track, and the distance between roads is the same. The construction of Qin Zhi Road has greatly facilitated domestic traffic;

5. Burning books to bury Confucianism, objectively unifying thoughts and avoiding the division of the country due to historical issues; However, the destruction of ancient books in various countries has made a considerable number of ancient cultural faults and ancient history in China dating, which is really regrettable;

6. The construction of Lingqu strengthens the control over the Pearl River Basin, making this area the territory of China forever;

7. Build the Great Wall to make it a natural dividing line between agricultural and nomadic peoples, and the Great Wall will become a national border for a long time;

8. Attack the Huns in the north and recapture the Hetao area, making this area the territory of China forever.

But there are also some negative effects.