i would imagine it would be something like post war development of scientific research institutions (JPL, Stanford) and defense industrial growth (Boeing) in California and Washington, which was pretty close to big military bases that saw a lot of returning people in the late 40s. i mean, my knowledge of these things is pretty amateur, but the fact that i can name a few organizations off the top of my head that were "Big" in the 50s, 60s during the explosion of the NSF as a reaction to the soviet space program eating the US' lunch... that kind of infrastructure and highly technical knowledge activity would probably go a long way to creating an environment that would be fertile for the future tech industry.

also, the coastal-ish california climate is kind of incredible, especially the mediterranean parts. mild winters, sunny and like 60s-70s with cooler nights. climate change is gonna wreck it, but i sometimes imagine how G it would be to be an overeducated and intellectually employed white guy in the 60s around coastal california, maybe even not far from san diego. like in a trailer or a bungalow on a mostly undeveloped beach kind of deal. ride a motorcycle down to TJ because the border is pretty chill back then, before the war on drugs.

granted, i am making all this shit up, but i read a book about chicago's founding/growth and it made a potent case for the importance of capital formations in geographic development (Chicago functioning as an aggregating market on the periphery of the "Great West" for large capital formations back on the East Coast... which themselves became what they were due to capital formations in London looking to extract from the colonies. so now my first move is to think about the "logic" of large piles of capital exercising influence over development.