Fallout isn't just about the world of the 50's in the future, it is specifically about the 50's "world of tomorrow" being nuked. It's a specialized fantasy setting, not a literal time progression... in any normal time where androids existed, computers would be a hell of a lot further on than DOS and a monochromatic screen. Logic doesn't really work with a high-fantasy idea like this, thus mapping a sequence of events that lead to Fallout's pre-war world is impossible.
I understand why those interested in cannon and lore want to try and ascribe a linear progession... I tend to want that as well... but I don't know if it's possible.