TELECOM Digest OnLine - Sorted: Re: Telephone Area Codes and Prefixes

Re: Telephone Area Codes and Prefixes

Neal McLain (
Thu, 15 Feb 2007 16:23:37 -0500

Joe Tibiletti <> wrote:

> ... Chicago had in the same period a 2L and 6N in some sub-urban
> area numbers in the same period.

PAT retorted:

> [TELECOM Digest Editor's Note: Neither 'suburban Chicago' nor
> anywhere else in (what is now) 312/630/773/815/847 or otherwise
> northern Illinois _ever_ had a total of eight digits for dialing; it
> was always (since 1923 or so) SEVEN digits, although the seven
> digits were parsed differently through the late 1940s ...

That's what I thought.

I don't believe that eight-digit numbers have ever been used anywhere
in the NANP. W. H. Nunn, writing in the September 1952 PSTJ, [*]
notes the wide variety in numbering plans that then existed in the
United States, and explains how they were all to become NPA+7D in the
form NPA+NNX+XXXX. He cites several examples of the "different types
of numbering plans" that existed in 1952, before conversion:

Philadelphia, PA (2L+5D)
Example: LOcust 4-5678

Los Angeles, CA (2L+4D and 2L+5D)
Example: PArkway 2345 and REpublic 2-3456

Indianapolis, IN (2D+4L)
Example: MArket 6789

El Paso, TX (2L+5D and 5D)
Example: PRospect 2-3456 and 5-5678

San Diego, CA (1L+5D and 1L+4D)
Example: Franklin 9-2345 Franklin 6789

Des Moines, IA (5D and 6D)
Example: 4-1234 and 62-2345

Binghamton, NY (5D)
Example: 2-5678

Manchester, CT (4D and 5D)
Example: 5678 and 2-2345

Winchester, VA (4D)
Example: 3456

Ayer, MA (3D and 4D)
Example: 629 and 2345

Jamesport, NY (3D)
Example: 325

Nunn doesn't mention New York or Chicago. I assume that by 1952,
these cities had already been converted from 3L+4D to 2L+5D.

Joe Tibiletti: can you provide a citation for your statement
eight-digit numbers existed in Chicago?

[*] W. H. Nunn. "Nationwide Numbering Plan." Bell System Technical
Journal, September 1952, 851-59. Manuscript received May 15, 1952.

Neal McLain

[TELECOM Digest Editor's Note: I will have to stand corrected on this.
Chicago was entirely manual until about 1938 or so. In those times,
numbers might have been _less_ than seven digits (and letters), but
they were never _more_ than seven. In other words, 'Sheldrake - 1'
would have been legitimate (telco did not 'force' filler or leading
zeros until automation started). When automation finally started, in
1938, Illinois Bell started printing all numbers (dialable or still
manual) in the telephone directory as names plus FOUR digits, using
leading zeros as required to complete the string. At that point in
time, SHEldrake -1 became SHEldrake 0001, etc. Telco said the
rationale for this was to 'begin educating the public' on the new
automated system being installed. Telco also stressed at that time
that '17' was 'one-seven' rather than 'seventeen', and that as another
example, '0700' was 'oh seven hundred' and not 'zero seven zero zero'
nor 'zero seven hundred' but you would think to be consistent if
'seventeen' was verbotin language that likewise 'seven hundred' would
be verbotin. But not as telco thought about those things, and we all
know that in every instance, Ma Bell always knew best. Zeros in the
first (thousands) position were always 'oh' and whenever they appeared
in the other three positions when non-repetitive they were also 'oh'.
When they repeated in the two final positions, they were to be
pronounced 'hundred'. If the second, third and fourth positions were
all zeros then they were pronounced 'thousand'. Although Chicago and
a few select suburbs began converting to dial in 1938, in early 1942
Western Electric Company was nationalized by the federal government
'for the duration' and that brought a screaming halt to any further
dial conversion. So from 1938 until 1946 Chicago was about 20-50
percent dial and the same amount manual. PAT]

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