How did Qin Shi Huang help create the first connected Great Wall system?

After unifying China in 221 BCE, Qin Shi Huang (the first emperor of the Qin dynasty) sought to consolidate his empire by removing internal fortifications that hindered administration and movement. To secure the northern border against the Xiongnu nomads, he ordered Gen. Meng Tian to link existing defensive wall segments previously built by the states of Qin, Yan, and Zhao.12

This massive project, which began around 214 BCE and lasted a decade, utilized hundreds of thousands of soldiers and conscripted workers to create what became known as the "10,000-Li Long Wall". By connecting these disparate barriers into a single, cohesive system, Qin Shi Huang established the first iteration of the Great Wall of China, setting a precedent for defensive infrastructure that subsequent dynasties would follow.13