Television burst onto the scene after the Second World War and soon became the most important mass medium.  But it had a long history before that:

Low Definition Television:
Francis Jenkins
 British low definition television

Television as we know it:
  Zwyorykin demonstrates electronic TV in 1930

 early tv
But they still needed FCC approval for commercial broadcasting (experimental noncommercial broadcasts were allowed).

 WNBQ Chicago, 1948

in 1947 the television boom began in earnest

 I Love Lucy (1951)

Further techonology:

this page written and copyright  © Pamela E. Mack
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last updated 10/31/05