Do you have a citation for this?
(I'm not necessarily doubting, it's just a claim I have not heard before).
Also google the “Clay report”, there’s a bunch of books and sources from there.
At this point, (1955) bombers and fission bombs were the threat. That’s why we had AT&T invest in hardened long lines facilities, shelters and duck and cover.
The reality of hydrogen bombs and ICBMs kind of took the wind out of sails of civil defense. You’re not going to drive out of Manhattan with 20 minutes notice and get to a place where you’ll survive. This really affected the people associated with this — the think tank guys at RAND and other places assumed they’d all be dead by the mid 1970s, and I can’t help to think that it didn’t affect their points of view.
We had a viable rail network all over the country as recently as the early 1950s. Federal policy blew it up because dispersing the population was seen as a civil defense priority for an atomic war, and cars and airplanes provided an economic engine to keep workers and returning soldiers employed.
Later, the shift to rural industry and trucking was a way to break unions. Meatpacking transformed from a good union gig back to an oppressive industry fueled by undocumented labor. If the workers acted up, the owners would realize they knew where a bunch of undocumented people lived and call in INS/ICE.