Between 1949 and 1961, nearly 20 percent of East Germany's population had defected to the West, causing a massive brain drain that threatened the communist economy.

Official Günter Schabowski erroneously announced that new visas for Western travel were effective immediately, prompting thousands to swarm unprepared border guards.

State Department advisors urged Reagan to remove this aggressive demand from his 1987 Brandenburg Gate speech, fearing it would ruin relations with the Soviets.

Known as the East Side Gallery, this 1.3-kilometer section features over 100 murals painted in 1990 to celebrate the peaceful end of the Cold War divide.