Source for old US telephone directories?

PeterWerner3

I hope this isn't too basic of a question, but in all of my genealogical research, one source that I've had trouble finding is old white and yellow pages from around the United States. My maternal grandparent's family lived in the Chicago area from the late 1920s to about 1960 and I'd love to be able to nail down an address history for their homes and the bakeries they owned. So if I wanted to find, say, a 1945 Chicago yellow pages or 1955 Flossmoor white pages, is there somewhere that I can search for these? Or have copyright issues from the companies that are successors to the various 'Baby Bells' prevented this?

Thanks!

Áine Ní Donnghaile

For Chicago, some links from my toolbox:
https://chicagogenealogy.org/news/8156475
https://libguides.chicagohistory.org/familyhistory/directories

Lawanna Dalley Casto

I've had success with City Directories on Ancestry for that time period. And I've also indexed Chicago city directories this year for FamilySearch.