Cold War - Wikipedia. Photograph of the Berlin Wall taken from the West side.
The Wall was built in 1961 to prevent East Germans from fleeing and to stop an economically disastrous migration of workers. It was a symbol of the Cold War and its fall in 1989 marked the approaching end of the war. The Cold War was a state of political and military tension after World War II between powers in the Western Bloc (the United States, its NATO allies and others) and powers in the Eastern Bloc (the Soviet Union and its satellite states).
Historians do not fully agree on the dates, but a common timeframe is the period between 1947, the year the Truman Doctrine (a U.S. policy pledging to aid nations threatened by Soviet expansionism) was announced, and 1991, the year the Soviet Union collapsed. Cold War in 9 Minutes.