Final answer:
The Berlin Wall was built in 1961 to stop East Germans from fleeing to the West and became a symbol of the Cold War. It was a physical and ideological divide until its fall in 1989, which marked the beginning of German reunification and the end of the Cold War.
Step-by-step explanation:
The Berlin Wall was constructed under Soviet direction on the night of August 12-13 in 1961, as a barricade to prevent East Germans from escaping to the West. This barrier separated East and West Berlin and became the official border between the two sides, representing a stark division between communist and capitalist ideologies. The Wall not only ended East-West migration but also stood as a symbol of the Cold War and the oppressive nature of the East German communist regime. On October 22, 1961, a significant stand-off occurred between the United States and the Soviet Union over the Allies' right to free movement in Berlin, testing the enforced boundaries. The Berlin Wall remained until November 1989 when miscommunication by an East German official led to its unexpected fall, catalyzed by jubilant citizens armed with sledgehammers, effectively beginning the process of reunification of Germany and the end of the Cold War era.