The Qin dynasty was the first dynasty to start connecting the various walls into a greater whole. That happened around 221 to 206 BC and was done under the reign of Qin Shi Huang. Though the wall was later improved still by other dynasties, it was during the Qin dynasty that the Great Wall of China was first formed into a cohesive structure.
South american civilization:
- The invention of various type of plants that could be used for medicinal purposes.
- The invention of various tools that could be used for artworks
Meso American civilization:
- The invention of early agricultural land structuring for irrigation system
- The invention of earliest calendar to distinguish time/period
North American civilization:
- Popularized the use of tobacco (now it become the most used drug in the world)
- Invent several techniques to raise animals.
