Library of Congress U.S. Telephone Directory Collection

The Library of Congress's collection of telephone directories represents the following states and localities: Alabama, Alaska, Arizona, Arkansas, California, Colorado, Connecticut, Delaware, the District of Columbia, Florida, Georgia, Hawaii, Iowa, Maryland, Pennsylvania, and the city of Chicago. The dates of the directories span most of the 20th century. The Library's United States telephone directory collection consists of 8,327 digitized reels of microfilm; of these, about 3,500 are presented in this collection. The remainder of the collection may be requested from the Microform Reader Services [[LJ 139).

https://www.loc.gov/collections/united-states-telephone-directory-collection/about-this-collection/

Cool subject but unfortunately I couldn't find anything related to Detroit or Michigan at Locations in U.S. Telephone Directory Collections.

If anyone can find something of interest there, please post a link!

Which is why I posted it in Non Detroit.