Built in 1961, the Berlin Wall stood for 28 years at the front line of the Cold War between the Americans and the Soviets. On Nov. 4, 1989, some 500,000 people gathered in East Berlin's central Alexanderplatz for the country's biggest pro-democracy protest. On Nov. 9, East Germany opened its heavily fortified border. Over the subsequent weeks and months, people chipped away at the barrier.
Scenes from Berlin in 1989 and Reagan's iconic speech in 1987: