Eh, it was obsolete by sometime in the 60s, e.g. when the SS-9 got accurate enough to take it out. In the '50s and '60s we had a real Civil Defense program, I

Eh, it was obsolete by sometime in the 60s, e.g. when the SS-9 got accurate enough to take it out. In the '50s and '60s we had a real Civil Defense program, I still have my mother's Civil Defense Block Mother sign from the end of that, when I was in 2nd grade. It was only later that CD -> FEMA and "crisis relocation" replaced sheltering, since it was cheaper. During the same decade we gave up on missile defenses....