Undated: Seven-digit telephone numbers

The Bell System is making the transition from alphanumeric telephone numbers ("PEnnsylvania 6-5000") to seven-digit numbers. The reason: to make more numbers available for the ever-increasing number of what were sometimes still called "telephone sets."

* "Mr. Digit and the Battle of Bubbling Brook" (Bell System film, 1961): @

* History of telephone prefixes (from privateline.com): @

* Telephone EXchange Name Project: @

* Time magazine article, May 11, 1962: @

* Time magazine article, July 13, 1962: @

* "The Let's All Call Up AT&T and Protest to the President March" (Allan Sherman song, 1963): @

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