This is everything i know.. hope it helps
During the early years of the Cold War, West Berlin was a geographical loophole through which thousands of East Germans fled to the democratic West. In response, the Communist East German authorities built a wall that The Berlin Wall was built to divide communist East Germany from democratic West Germany and to keep East Germans from escaping to West Germany. After World War II, defeated Germany was divided into four zones, each occupied by Allied forces: the United States, France, Great Britain and the Soviet Union totally encircled West Berlin. It was thrown up overnight, on 13 August 1961.