In 1926 the Post Office Department issued the first in a series of airmail stamps that no longer featured the square shape of the first six airmail stamps. The reason for a new horizontal rectangle shape, or long stamp, was simple—postal clerks needed to easily distinguish airmail letters from regular mail. With the changing domestic airmail rates, new colors were added to further ease identification.
The first series in the new rectangle shape featured a topographical map and two de Havilland DH-4 biplanes in flight (C7-9). The 10-, 15-, and 20-cent issues of 1926-1927 paid complicated rates based on zones and combinations of different contract routes until a simplified flat-rate system was initiated on February 1, 1927. The popular Charles A. Lindbergh 10-cent issue of 1927 featured his Spirit of St. Louis airplane, which he flew solo non-stop across the Atlantic Ocean that year (C10). By 1930 a new Winged Globe series began to replace the larger 5-cent Beacon airmail stamp. 5-, 8-, and 6-cent stamps provided lower-priced domestic airmail service than in previous decades (C12, C16, C17, and C19). Depicting a globe with extended wings, the design replicated the insignia of the pilots who had carried the mail in a tribute to them. The final stamp in the Winged Globe series paid the thirty-cent rate for the newly-inaugurated transatlantic airmail service (C24).
Captain Benjamin B. Lipsner, The Airmail Jennies to Jets (New York: Wilcox & Follett, 1951).
Perham C. Nahl, Ed., American Air Mail Catalogue, vol. 5 (Cinnaminson, N.J.: American Air Mail Society, 1985).
The Airpost Journal, American Air Mail Society.
Mekeel’s Weekly Stamp News.
Scott Specialized Catalogue of United States Stamps & Covers (Sidney, Ohio: Scott Publishing, 2006).
Stamp Design Files, Bureau of Engraving and Printing, Washington, D.C.
Stamp Design Files, Smithsonian National Postal Museum, Washington, D.C.