Explore Chicago Collections
https://explore.chicagocollections.org/records/?f2-cities=Elgin&f5-types=Archival+Collections&browse-topics=yes&f1-cities=Elgin&f3-topics=Work%3A%3AAdvertising&f7-topics=Work%3A%3AAdvertising&f6-institutions=University+of+Chicago&f4-institutions=University+of+Chicago&sort=title