The public's fascination with aviation and technology became clear to the Post Office Department by the late 1920s. As a consequence, the POD added a new theme to its commemorative categories, one that paid tribute to the nation's technological acumen.
In conjunction with the 25th anniversary of the Wright brothers' historic flight and the 1928 International Civil Aeronautics Exhibition in Washington, DC, the POD issued two stamps commemorating "civil aeronautics." In addition, it celebrated American ingenuity in 1929 by issuing a commemorative stamp on the 50th anniversary of Thomas Edison's invention of the electric light bulb. The 2-cent Edison stamp was issued in both sheet and coil formats.