RADIO WAS THE first mass medium. Before broadcasting, home entertainment was limited to card games, board games, sing-a-longs, newspapers, and magazines. No newspaper had national distribution as the New York Times, USA Today, and Wall Street Journal do now. There were too many magazines for large numbers of readers in any community to read the same few. The only electronic medium was the family phonograph, the forerunner of CD players and downloads, but the sound was only heard in the same room. Phonographs were media, but not a mass media.

There were shared entertainments outside the home such as cinema, concerts, plays, dances, lectures, church socials, and athletic events, but it would be a stretch to call these “mass.” While many people would see a Charlie Chaplin film, the neighbourhood did not attend together. It was not until radio sets were brought into the home that a media became mass, for you and many of your neighbours, schoolmates, and co-workers enjoyed the same programs at the same time. The New York Times was effusive on November 12, 1921 describing the first address to the nation by an American president, Warren G. Harding: “The very voice of the President of the Republic can be heard by tens of thousands of people, in hall and park and street, at the selfsame moment in New York and San Francisco.” In the earliest days, there were only local stations but within a few years broadcasters joined to carry events such as Harding's speech. However, these “chain” broadcasts, as they were called, are better understood as ad hoc stations signing on for a single broadcast or the joining of a few small stations in a geographical area. It took the networks to make regular programming national, starting in 1926.

George H. Douglas notes that most homes acquired a radio during the Great Depression (1929– 1939), “masses of people lacked the money to go out for dinner or to a nightclub. Staying home became an obligatory form of relaxation, but one that could be made enjoyable by the purchase of an inexpensive radio.” Radio dominated recreation time the way that television later did and internet content increasingly does. Charles A. Siepmann summarized radio's impact well, “here in America radio is our main pastime. More than 90 percent of American homes have at least one receiving set. Millions have several.