Up In the Sky! (16)

Superman: the Unauthorized Biography by Glen Weldon.

The Silver Age as
the bottled city, Kandor.
A great metaphor.

I wrote a review of Superman: the Unauthorized Biography for Tor.com, so you can read it there.
I mentioned the Tye book, & the De Haven book, so I'll link to them here; & to Supergods, for good measure.