The origins of carrier multiplexing: Major George Owen Squier and AT&T

George O. Squier, the inventor of the Muzak system, was the inventor as well, in 1910, of telephone carrier multiplexing, the forerunner of microwave frequency multiplexing after World War II, and its current incarnation as optical wavelength multiplexing. Squier was a Major in the United States Army Signal Corps at the time, later becoming Major General and Chief Signal Officer. His invention was initially rejected by AT&T engineers as not being commercially viable. This view was not shared by others in the engineering community, including John Stone Stone, a distinguished independent telephone engineer. After prodding by Stone, AT&T officials began a reappraisal of the "wired wireless" system, as Squier chose to call it, and by 1914 development of a commercial system, was underway. By 1918, however, when the AT&T system went into service, AT&T was claiming that Squier\´s work had only been "suggestive" and that its system was based on inventions of its own engineers. We describe the sequence of events, beginning with Squier\´s invention, that led to the AT&T commercial rollout of carrier multiplexing. We also offer some possible reasons, based on archival documents, as to why AT&T downplayed Squier\´s invention.