why did they build the Great Wall and how many people died making the wall, how?

It was built to protect the people and territories south of the wall from a continued threat of invasion by the northern nomadic tribes.

As the construction of that lasted for over 2,000 years, many people died for making that, but the exact amount is unknown. Maybe due to being overworked, some died from illness and some died from being exhaust.

wow thats crazy!!!!!!!!!!