Which dynasty in China begin rebuilding the Great Wall of China

Qin Dynasty

The Great Wall of China's history began in the Spring and Autumn Period (770–476 BC), was first completed in the Qin Dynasty (221–206 BC), and was last rebuilt as a defense in the Ming Dynasty (1368–1644).

they sometimes resort to unethical tactics.

in 1897, pershing became a tactical officer at west point, and that's where he was given the nickname "black jack." pershing's first name is "john," for which "jack" is a nickname, and he was a white man who commanded black troops. hence "black jack".