Explore Chicago Collections
https://explore.chicagocollections.org/records/?f3-cities=Chicago&f2-topics=Natural+%26+Built+Environments%3A%3AAir+Travel&f4-topics=Natural+%26+Built+Environments%3A%3AAir+Travel&f1-topics=Events+%26+Movements%3A%3AFairs+%26+Conventions