Postcard photo of an Eastern Air Lines meal circa 1950s.
Eastern Air Lines
Not mailed.  This was a <a href="https://en.wikipedia.org/wiki/Lockheed_Constellation" class="extiw" title="en:Lockheed Constellation">en:Lockheed Constellation</a>, which were common passenger planes during this time period.  In the 1950s and 1960s, these planes began to be replaced by jets.  The last regularly scheduled Constellation commercial flight was in 1967.
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