The history of the Great Wall of China began when fortifications built by various states during the Spring and Autumn (771-476 BC) periods (475-221 BC) were connected by the first emperor of China, Qin Shi Huang, to protect his newly founded Qin dynasty (221-206 BC) against incursions by nomads from Inner Asia. The walls were built of rammed earth, constructed using forced labor, and by 212 BC ran from Gansu to the coast of southern Manchuria. You can get HISTORY of Great Wall of China | Length and Facts.
The Spring and Autumn Period (770–476 BC):
It is said that the first parts of the Great Wall were built during the Spring and Autumn Period, when the eastern and central region of what is now China consisted of many small states or princedoms.
To protect their states the princes ordered independent walls be built along state borders. These were like the Great Wall in construction, but on a smaller scale. The earliest was probably built between the states of Lu and Qi around 650 BC, which later became part of the Chu State Wall.
The Warring States Period (475–221 BC):
As rival states fought for territory and power, the influence of the Zhou kings waned. The small states were joined together by warlords by the beginning of the Warring States Period to form seven large states. (Chu, Qi, Wei, Yan, Zhao, Qin, and Han). Each state had its own defensive walls, like several short Great Walls. Click for the walls of the Qi, Wei, Yan, and Zhao states.
The Great Wall of the Ming Dynasty:
The sign for the Great Wall in todays China Atlas signifies the youngest Great Wall of the Ming Dynasty (1368-1644). During Mings reigning time of more than 270 years, the government never broke down the construction and maintenance of the Great Wall. The massive Great Wall construction in the dynasty was over 50 times, and the Great Wall went to its summit in times of war and peace during the Ming Dynasty.