Boeing 727s were used by American Airlines to add service from its Chicago hub to Harrisburg, Pennsylvania on July 2, 1984. The service was a result of American Airlines obtaining landing slots at O’Hare which were not being used by other airlines.

This cover was carried on the American Airlines inaugural flight from the O'Hare Airport Mail Facility in Chicago, Illinois to Harrisburg, Pennsylvania (where it was backstamped) and is listed in The American Air Mail Catalogue as AA-D166Ef.