“and the plane went on to spy for the CIA until 1974”
They were operating them through the 80s because i used to see them fairy constantly coming into Burbank right past where I kept my airplane in the middle of the night with no lights for maintance at the Skunk Works.
I thought this was about the band U2 being on the CIA payroll.
The Dragon lady
The U-2 was certainly useful, but was not a success at photographing the USSR, as Gary Powers discovered. Only satellites were successful at that.
http://www.nbcnews.com/science/area-51-its-purpose-declassified-no-ufos-lots-u-2-6C10931555
Kelly Johnson and John Moses Browning represent the best examples of American genius. The SR-71 Blackbird like the 1911 pistol and 50 cal. machine gun are machines that cannot be improved upon even decades after their creation and despite giant leaps in design technology.