Perhaps the biggest impact the U-2 Spy Plane had, was during the "U-2 Incident". Pilot, Gary Powers, was flying over the Soviet Union on a spy mission. However, Soviet's spotted his plane and shot it down. President Eisenhauer, and Soviet Leader, Khrushchev, had scheduled a meeting before this, for a few weeks later. After this occurred Eisenhauer lied and said it was just a weather plane. He was caught in his lie, and Khrushchev immediately called off the meeting, which prolonged the Cold War.
Now aside from the negative impact that it had, it had fifty times more positive impacts. A huge impact was the intelligence that it gathered while flying over Cuba. The U-2 spotted the Soviet's in Cuba, building missiles. This helped the United States to put a stop to it, and end the Cuban Missile Crisis.