Probably WWII, with the American radar research program (not as famous as the Manhattan Project but probably equally or more important) centered there.
Gunsights too. That was how Doc Draper who later pioneered inertial navigation and whose lab designed the Apollo Guidance Computer first made his name. (Draper Labs is no longer formally affiliated with MIT as it was divested during the Vietnam War.)
But WWII was probably a major catalyst in the US to the rise in prominence of all the great science and engineering research universities. (There are actually a lot of inventors from that era like Draper who although they were also theoreticians to some degree one suspects might not fit in with a modern research university faculty.)
But WWII was probably a major catalyst in the US to the rise in prominence of all the great science and engineering research universities. (There are actually a lot of inventors from that era like Draper who although they were also theoreticians to some degree one suspects might not fit in with a modern research university faculty.)