The SR-71 Blackbird was developed in the late '50th and early '60th at the 'Skunk works' at Lockheed. The line started with the Lockheed A-12, which took to the sky in 1962. In a way it was one of the first plane in which stealth was one of the desired faculties. Along with high altitude and high speed it was meant to make the plane more or less invulnerable to countermeasures. Like the U-2, it was designed for over flight reconnaissance. In the wake of the U-2 incident in Russia, an agreement was signed between the U.S. and the U.S.S.R., that prohibited these over flights. Thus the SR-71 was developed, with side way looking radar and camera's, and a 2 men crew. The first SR-71 flew in 1964. All in all, 36 or 38 of these planes were built, and they served for over 35 years all over the world.