According to historical records, since the Warring States period, more than 20 vassal states and feudal dynasties have built the Great Wall. The first is Chu, which began to build the Great Wall to defend the northern nomadic people or enemy countries. Later, countries such as Qi, Yan, Wei, Zhao and Qin began to build their own Great Wall for the same purpose. After Qin unified the six countries, Qin Shihuang sent a famous soldier, Meng Tian, to explore the Xiongnu in the north, connecting the Great Walls of various countries, stretching for more than 10,000 miles from Yao in the west to Liaodong in the east, hence the name "Wan Li Great Wall".
Qin Changcheng: In the thirty-third year of Qin Shihuang (2 14 BC), he sent general Meng Tian to drive the Xiongnu to the north, and built the Great Wall from Lintao (now Min County, Gansu Province) in the west to Liaodong in the east to stop the Xiongnu from going south, which was called Qin Changcheng in history. But now only the remains are left.
Han Great Wall: The Great Wall continued to be built in the Han Dynasty. From Wendi to Xuan Di, it was built into a Great Wall, starting from Dawaner Shicheng in the west and reaching the north bank of Heilongjiang in the east. It is the longest Great Wall in the history of China, more than 10,000 miles long. Its pavilions and beacon towers extend westward to Lop Nur, Xinjiang. Half of the ancient Silk Road was along the Great Wall.
Great Wall in Ming Dynasty: In order to prevent the invasion of Tatars and Waci people, the construction of the Great Wall never stopped. During the period from Hongwu to Wanli, after 20 large-scale constructions, a side wall of 6,700 kilometers was built from Jiayuguan in Gansu in the west to Hushan in Liaodong in the east. It is the Great Wall with the largest scale, the strongest project and the most perfect function in history, and it is also a relatively well-preserved Great Wall now. What we see today is mainly the Ming Great Wall.