Answer:
The Wall cut off West Berlin from surrounding East Germany, including East Berlin.
The Berlin Wall was built to prevent its population from escaping Soviet-controlled East Berlin to West Berlin
The Americans, British, French, and Soviets formed Germany after WW2.
They wished to improve their living conditions and opportunities in the West.
It was on 9 November 1989. The fall of the Wall marked the first critical step towards German reunification.