Here is a peak at Hinsdale's past. I found an old picture of the greenhouse before most the houses were built around the neighborhood. The greenhouse was used as a marker when the first airplane pilots were establishing commercial aviation routes throughout the country. In the below photograph you can see a giant arrow underneath a tower that pointed the way to Midway Airport. The airport, originally called Chicago Air Park, was built in 1923 to serve as an airmail stop.
“Beginning in 1923, a system of tower-mounted light beacons was installed along the Transcontinental Air Mail Route, which connected New York and San Francisco.
The 51 foot tall towers were placed at 10 mile intervals and each was topped by a 1 million candlepower rotating lamp that was visible within a 40 mile radius. Two additional color-coded course lights pointed up and down the airway and flashed a Morse code letter that identified the beacon.
To enhance daytime navigation, most beacon towers were built atop large concrete arrows, which pointed in the direction of the next beacon. This arrow/beacon system grew exponentially when the Air Mail Act of 1925 required that Air Mail service be contracted out to various commercial airlines.”
-Tooele Transcript Bulletin July 8, 2010