Capital Airlines inaugurated the first scheduled U.S. air mail service using British Viscount turbo-prop planes on July 26, 1955.

This cover was carried on the inaugural Jet flight from the Pittsburgh, Pennsylvania Airport Mail Facility to Chicago, Illinois (where it was backstamped) and is listed in the Jet Age Flights Section of The American Air Mail Catalogue as J-6f.

On June 1, 1961, Capital Airlines was formally merged into United Air Lines.