The Soviet Union's success of sending a man into space in 1961 resulted in President Kennedy making it a goal to land a man on the moon before the end of the decade.
After the trip by Yuri Gagarian (Soviet astronaut), Kennedy knew that the US needed a drastic measure to pass the Soviet Union in the "space race." This is why Kennedy proposed in a session to Congress that the US should have the goal to put a man on the moon before the end of the decade. This goal results in the funding of the Apollo Program, which is meant to accomplish Kennedy's goal. The US does accomplish this goal in July of 1969 when American astronaut Neil Armstrong becomes the first man on the moon.