As for the own-airplane-building, It may have more to do with the US-basing of the aircraft companies than anything else. The actual component manufacture etc. could happen in many different places.
Remember the Concorde... We had the Blackbird SR/RS-71, but it was sort of like the Apollo missions... a great leap forward, and then we realized we were more comfy back at the last step :p
(I say SR/RS because the original designation was the RS-71, but the president at the time said it wrong in a speech, so rather than admit a mistake, they changed all of the blueprints, tech specs, everything, to reflect the new SR-71 name.... heh)
