The Great Wall of China was built between the 7th and 8th century BC by 3 dynasties. It was made with stones, rammed Earth, clay, sand, soil and bricks. Since the wall was started it has been rebuilt, modified and extended through China. The Great Wall of China is 21,196.18 kilometres long and many different groups worked together in the construction. Between the workers were soldiers, war prisoners, slaves, convicts and even criminals and common people. The wall was built initially to protect the region from invasions and for military purposes, however it also helped protecting the economy and the agriculture and the cultural progress itself. The Great Wall of China includes watch towers, guardhouses, castles, gates and forts, barracks and beacon-towers. In the year 1987 The Great Wall was declared a UNESCO World Heritage Site.
The Great Wall of China is a series of fortifications made of stone, brick, tamped earth, wood, and other materials, generally built along an east-to-west line across the historical northern borders of China to protect the Chinese states and empires against the raids and invasions of the various nomadic groups of the Eurasian Steppe with an eye to expansion. Several walls were being built as early as the 7th century BC these, later joined together and made bigger and stronger, are collectively referred to as the Great Wall Especially famous is the wall built in 220–206 BC by Qin Shi Huang, the first Emperor of China. Little of that wall remains. The Great Wall has been rebuilt, maintained, and enhanced over various dynasties; the majority of the existing wall is from the Ming Dynasty (1368–1644).
umm well I think that a way that environmental factors have affected the human population since 1900 is that as the environment probably gets worse then it could effect the human population idk I hope that I helped in any way
