Note that overflights of the USSR started well before the U-2. As early as 1946, the US was flying reconnaissance planes (usually modified strategic bombers) ov

Note that overflights of the USSR started well before the U-2. As early as 1946, the US was flying reconnaissance planes (usually modified strategic bombers) over the Soviet Union. The U-2 came about because the Soviets began to gain the ability to intercept and possibly shoot down those flights.