Which books have the latest info on Chicago, looking for help to flesh out the city's background for when running missions.

Feral Cities (SR4) I believe.

Bug City is an awesome setting - had a lot of fun in it.

Thanks, my potential players don't know much of the bug city history thankfully

And remember, live in Seattle once, but leave before it makes you hard and live in Chicago once, but leave before it turns you into a bug.

How can you even think of going to a city that does not have real pizza?

If you want to go even further back, one of the earliest SR novels is set in Chi-town, back before Bug City was even a thing. Changeling, by Chris Kubasik covers the exploits of a late-awakening troll from 2039 to 2052. One of the absolute best resources for how late goblinization looks from the inside, too.

Important notes are the Sears Tower being bombed by Alamos 20k, resulting in the Second Chicago Fire and creating the Shattergraves section of the resulting mid-town Barrens known as The Noose.

All Chicago sourcebooks are available as PDFs through Drive-thru.

Neo-Anarchist's Guide to North America - 2050 Chicago (Plus New York, Atlanta, and a couple other locales).
Bug City - What the name implies. 2053 Chicago.
Target: UCAS - Chicago, Boston, and New Orleans. Covers the "end" of the Bug City storyline. 2056.
Feral Cities - Chicago and a couple others I'm blanking on right now. 2070 Chicago.

Also the novels 2XS (Set in 2050 or '51) and Burning Bright (2053) are set in Chicago.

Yay on the latter, nay on the former.
2XS is set in Seattle, as is the Universal Brotherhood storyline on which it is build.

Although Montgomery is in communication with a Chicago based Johnson somewhere in the book, IIRC.

Burning Bright's mostly in Hawaii, isn't it?

You're thinking of House of the Sun

Indeed I am. Been a while since I re-read those.

Yeah, I'm getting my titles confused. I meant Changeling, which had already been pointed out.

yay i'm reading all those books right now! though i put down the house of the sun though, all the Hawaiian folk lore was just giving me a headache