i want to know what the great wall of china was made for and who built it and year was complete

Materials: stone, bricks, earth even wood.

Who: With the order of the emperors, soldies, peasants, slaves, prisoners and common people were engaged in building the wall.

When: the construction of the wall lasted for about 2,000 years. According to the records, the earliest sections were made during the warring states period. During Qin Dynasty, Qin Shihuang ordered to join the former sections. The latest and best preserved ones were made in Ming Dynasty.