1st Emperor of United China, QinShiHuang(18Feb259–10Sep210 BC) standardized measurement,currency,Chinese script,built Great Wall

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The First Emperor of United China, Qin Shi Huang (18 February 259 BC – 10 September 210 BC) became the King Zheng of Qin when he was 13, then China's first emperor when he was 38 after the Qin had conquered all of the other Warring States and unified seven warring states of China in 221 BC. His public works projects included the unification of diverse state walls into a single Great Wall of China and a massive new national road system.

Qin Shi Huang and Li Si unified China economically by standardizing the Chinese units of measurements such as weights and measures, currency, and the length of the axles of carts to facilitate transport on the road system.

The emperor also developed an extensive network of roads and canals connecting the provinces to improve trade between them. The currency of the different states were also standardized to the Ban liang coin. Perhaps most importantly, the Chinese script was unified. Under Li Si, the seal script of the state of Qin was standardized through removal of variant forms within the Qin script itself. This newly standardized script was then made official throughout all the conquered regions, thus doing away with all the regional scripts to form one language, one communication system for all of China.

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Image courtesy Wikipedia and psu.edu