Here’s a blast from the past that is technically a chart:
I saw this on Twitter the other day, but I don’t remember where. So apologies to whoever posted it.
The addition of the term “defense” in the act’s title was for two reasons: First, some of the original cost was diverted from defense funds. Secondly, most U.S. Air Force bases have a direct link to the system. One of the stated purposes was to provide access in order to defend the United States during an attack. All of these links were in the original plans, although some, such as Wright Patterson were not connected up in the 1950s, but only somewhat later.
Cities back then were seen as weaknesses simply because their density made them theoretically easy targets for Russian nukes. Freeways and driving were one solution to the threat of nuclear war.
Actually, however, automobiles do not make good bomb shelters. Or so I have been told… Do not use your car as an atom bomb shelter.