Contrary
to popular belief, there were no central office prefixes in the beginning. To place a call on June 26, 1878, when the Bell-licensed
Chicago Telephonic Exchange first opened, the subscriber merely told the
operator the name and address of the party desired.
For purposes of
identification, the original telephone switchboard at 125 LaSalle St. was known
as the Central office. Two more offices soon opened and were called the Halsted
Street branch and the Canal Street branch.
Telephone switchboard operator, Washington Island, Wisconsin, 1915. |
By
1883, these three central offices had grown to 11, and around that time the Bell
System-affiliated Chicago Telephone Company (formed in 1881) began to refer to
most of them by number. Thus, the switchboard at 125 LaSalle St. became known
as the № 2 office. By then, too, subscribers were requested to call by number
rather than by name.
Chicago telephone switchboard in the 1880s. (photo via Illinois Bell) |
The
initial digit of the phone number generally indicated the telephone central office;
that is, the subscriber who had “3123”
as the call number was served from № 3 office at Chicago Ave. and Clark St. The
three offices lying just outside the city limits had no numerical designation and
were known as Stock Yards, Oakland and Ravenswood. In 1889, Stock Yards was
changed to Yards and Ravenswood to Lake View. In that same year, telephone
growth brought about the first use of 5-digit numbers, the Oakland series
running from 9800 to 10,999 and the Lake View series from 12,001 to 12,499. This
first call number system was inflexible, however, because it allowed little
latitude for growth.
By
1892, on the eve of the opening of the World’s Columbian Exposition, it became
apparent that the city was rapidly outgrowing the old numbering scheme, and in
that year the change to a system of combined prefix and number was made. Beginning
February 15, a subscriber served from № 3 office had his/her number change
from “3123” to “North 123.” The entire
list of changes:
Old
Designation Serving #s Changed to
№ 2 office 1 to 2999 Main 1
to Main 2999
№ 3 3001 to 3999 North 1 to North 999
№ 4 & 5 4000 to 5399 Main 4000 to Main 5399
№ 7 7001 to 7999 West 1 to West 999
№ 8 8001 to 8999 South 1 to South 999
№ 9 9001 to 9499 Canal 1 to Canal 499
Yards 9500 to 9799 Yards 500 to Yards 799
Oakland 9800 to 10,999 Oakland
800 to Oakland 999
Lake View 12,001 to 12,499 Lake
View 1 to Lake View 499
Telephone
numbers, therefore, started using the central office name as the prefix. This second
system remained in effect for nearly 30 years.
Early switchboard operator, 1880s. |
Certain names, such as “Monticello,” were replaced because their numerical equivalents, in this case, “666,” conflicted with other existing offices, like “Monroe.” As a result, “Monticello” became “Juniper.” This change was necessary for the launch of automatic dial service, first introduced in Chicago with the cutover of “CENtral” prefix (in the Franklin Building at 315 W. Washington St.) on June 9, 1923.
The
following is the complete list of Chicago and Evanston central office exchange names and
their corresponding prefixes, adopted in 1948.
This system allowed for additional
prefix equivalents without the invention of new exchange names.
Rotary Dial |
Two 17-year-old teenagers were baffled by a rotary phone. A must-watch video.
Telephone operators, 1950s. |
ALbany............. AL 2
AMbassador......... AM 2
ANdover............ AN 3
ARdmore............ AR 1
ARmitage........... AR 6
ATlantic........... AT 5
AUstin............. AU 7
AVenue............. AV 2,3&6
BAyport............ BA 1
BElmont............ BE 5
BErkshire.......... BE 7
BEverly............ BE 3&8
BIshop............. BI 2&7
BIttersweet........ BI 8
BOulevard.......... BO 8
BRiargate.......... BR 4
BRoadway........... BR 3,4&5
BRoadway........... BR 3,4&5
BRunswick.......... BR 8
BUckingham......... BU 1
BUtterfield........ BU 8
CAlumet............ CA 5
CAnal.............. CA 6
CApitol............ CA 7
CAthedraL.......... CA 8
CEdarcrest......... CE 3
CEntral............ CE 6
CHesapeake......... CH 3
CLiffside.......... CL 4
COlumbus........... CO 1
COmmodore.......... CO 4
COrnelia........... CO 7
CRawford........... CR 7
DAnube............. DA 6
DAvis.............. DA 8
DEarborn........... DE 2
DElaware........... DE 7
DIckens............ DI 2
DIversey........... DI 8
DOrchester......... DO 3
DRexel............. DR 3
EAstgate........... EA 7
EDgewater.......... ED 4
ELmdrive........... EL 6
ENglewood.......... EN 4
ESsex.............. ES 5
EStebrook.......... ES 8&9
EVerglade.......... EV 4
FAirfax............ FA 4
FInancial.......... FI 6
FIre............... FI 7
FRanklin........... FR 2
FRontier........... FR 4&6
FUlton............. FU 5
FUlton............. FU 5
GArden............. GA 4
GLadstone.......... GL 5
GRaceland.......... GR 2&7
GReenleaf.......... GR 5
GRovehill.......... GR 6
HArrison........... HA 7
HAymarket.......... HA 1
HEmlock............ HE 4&6
HIlltop............ HI 5
HOllycourt......... HO 5
HUdson............. HU 3,7&8
HUmboldt........... HU 6&9
HYde Park.......... HY 3
INdependence....... IN 3
INterocean......... IN 8
IRving............. IR 8
JUniper............ JU 3&8
KEdzie............. KE 3
KEnwood............ KE 6&8
KEystone........... KE 3&9
KIldare............ KI 5
LAfayette.......... LA 1,2&3
LAkeview........... LA 5&8
LAwndale........... LA 1&2
LIncoln............ LI 9
LIvingston......... LI 8
LOngbeach.......... LO 1
LUdlow............. LU 2&5
LUdlow............. LU 2&5
MAnsfield.......... MA 6
MErrimac........... ME 7
MIchigan........... MI 2
MIdway............. MI 3
MItchell........... MI 6
MItchell........... MI 6
MOhawk............. MO 4
MOnroe............. MO 6
MUlberry........... MU 5
MUseum............. MU 4
NAtional........... NA 2&5
NEvada............. NE 2&8
NEwcastle.......... NE 1
NOrmal............. NO 7
OAkland............ OA 4
OFficial........... OF 3
ORchard............ OR 3&6
ORchard............ OR 3&6
PAlisade........... PA 5
PEnsacola.......... PE 6
PLaza.............. PL 2
POlice............. PO 5
POrtsmouth......... PO 7
PRescott........... PR 9
PRescott........... PR 9
PRospect........... PR 6&8
PUllman............ PU 5
RAdcliffe.......... RA 3
RAndolph........... RA 6&7
RAvenswood......... RA 8
REgent............. RE 1&4
REliance........... RE 5
REpublic........... RE 7
ROckwell........... RO 2
ROdney............. RO 3
ROgers Park........ RO 1&4
SAcramento......... SA 2
SAginaw............ SA 1
SEeley............. SE 3&8
SHeldrake.......... SH 3
SOuth Chicago...... SO 8
SOuth Shore........ SO 8
SPaulding.......... SP 2
SPring............. SP 4,5&7
STate.............. ST 1&2
STewart............ ST 3
SUnnyside.......... SU 4
SUperior........... SU 7
TAylor............. TA 9
TRiangle........... TR 3&4
TUxedo............. TU 9
UNderhill.......... UN 7
UNiversity......... UN 4,6&9
UNiversity......... UN 4,6&9
UPtown............. UP 8
VAn Buren.......... VA 6
VIctory............ VI 2
VIncennes.......... VI 6
VIrginia........... VI 7
WAbash............. WA 2
WAgner............. WA 4
WAlbrook........... WA 5
WAterfall.......... WA 8
WEather............ WE 4
WEbster............ WE 9
WEllington......... WE 5
WEntworth.......... WE 6
WHitehall.......... WH 3&4
YArds.............. YA 7
At
that point, the Chicago alphabetical directory (White Pages) showed all local numbers in the
city to be in the now-familiar 7-digit format still in use today (such as “236-1234”).
Exchange
names continued appearing in some Chicago Yellow Pages and advertisements into the 1980s.
In
the original North American Numbering Plan of 1947, all of the Chicago area was
covered by area code 312, the rest of northern Illinois was 815, central
Illinois was 217, and southern Illinois was 618.
Reasons why people tend to remember their first telephone number, no matter how old they are.
Safety and Security: Parents, teachers, and community safety programs emphasize the importance of children memorizing their home telephone numbers at a young age. This was done as a safety measure so that children can contact their parents or guardians in case of an emergency or if they get lost. This early and frequent repetition can make the number stick in a person’s memory, possibly forever.Repetition and Usage: The first telephone number that one learns is often used repeatedly over a long period of time. This frequent repetition can engrain the number in one’s memory.Significance: The first telephone number is often associated with one’s childhood home or a significant period in one’s life, which can make the number more memorable.Necessity: In the past, before the advent of smartphones and digital contact lists, people had to memorize or write down important phone numbers. This necessity could have contributed to the long-term retention of these numbers.
However, the need to memorize phone numbers has significantly decreased with the advent of smartphones and digital contact lists. Many people today do not remember phone numbers because they rely on their devices to store and dial them.
ADDITIONAL READING: The Chicago Telegraph arrived in 1848. It becomes the eastern terminus of “Western” communication.
Compiled by Dr. Neil Gale, Ph.D.