Just as the Soviet Union beat the United States into space with Sputnik in 1957, so it was first to send an astronaut into space in 1961. The Soviet cosmonaut's name was Yuri Gagarin, went aloft in the spaceship Vostok 1 on April 12, 1961, at 9:07 AM. He orbited the Earth once in one hour and 29 minutes, reaching a maximum altitude of 187 miles (301 kilometers). The ship landed the same day at 10:55 AM. It was Gagarin's only space flight.

This move by the Soviet Union prompted the United States to put more energy behind its Mercury program, which was also attempting to put a man into space. On May 5, 1961, Alan Shepard became the first American in space, and in February 1962 John Glenn became the first American to orbit the Earth.

The space race heated up, with the moon as one of its immediate goals. This goal was reached on July 20, 1969, when American Neil Armstrong became the first person to set foot on the moon.

The most striking symbol of the Cold War was the Berlin Wall. Its purpose was to keep East Germans from fleeing to the West to escape the oppressive Communist dictatorship of East Germany. Construction of the wall was started on the night of Aug. 12-13, 1961. It began as a barrier of barbed wire and cinder blocks but was eventually turned into a series of concrete slabs 15 feet (5 meters) high and topped with barbed wire and guard towers. It surrounded West Berlin, since the city was itself surrounded by East Germany.

In spite of the wall, about 5,000 East Germans managed to escape across it, but 191 persons were killed trying to get away. When the Communist regime in East Germany began collapsing in the autumn of 1989, the wall was opened on November 9. With the unification of the two Germanys in 1990, the wall was demolished.