Serving the steel centers of the Midwest, this route was inaugurated with service provided by three Waco 9 biplanes. The Cleveland terminal was the Glenn Martin Airplane Factory Field. Pittsburgh and McKeesport both dispatched mail through Bettis Field in McKeesport. Shortly thereafter, Youngstown was dropped from the schedule as Lansdowne Field was found unsatisfactory. Youngstown was later restored to Contract Air Mail Route 11 service on September 7, 1928, when this condition was remedied.

The contract for this route was awarded on March 27, 1926. Initial service along this 123-mile route was one daily trip each way.

This cover was carried on the April 21, 1927, inaugural Contract Air Mail Route 11 flight from Youngstown, Ohio to Cleveland, Ohio (where it was backstamped) and is listed in the Contract Air Mail Flights (CAM) Section of The American Air Mail Catalogue as 11N2.

On October 25, 1930, Clifford Ball was taken over for $137,000 by Pittsburgh Aviation Industries Corporation and renamed Pennsylvania Air Lines (PAL). 

Pennsylvania Airlines merged with Central Airlines on November 1, 1936 to become Pennsylvania-Central Airlines

Pennsylvania-Central Airlines changed its name to Capital Airlines on April 28, 1948.

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