Illinois Bell is the name of the Bell Operating Company serving Illinois

Illinois

Illinois is the fifth-most populous state of the United States of America, and is often noted for being a microcosm of the entire country. With Chicago in the northeast, small industrial cities and great agricultural productivity in central and northern Illinois, and natural resources like coal,...

. It is wholly owned by AT&T.

Their headquarters are at 225 West Randolph St., Chicago

Chicago

Chicago is the largest city in the US state of Illinois. With nearly 2.7 million residents, it is the most populous city in the Midwestern United States and the third most populous in the US, after New York City and Los Angeles...

, IL. After the 1984 Bell System Divestiture

Bell System divestiture

The Bell System divestiture, or the breakup of AT&T, was initiated by the filing in 1974 by the U.S. Department of Justice of an antitrust lawsuit against AT&T. The case, United States v...

, Illinois Bell became a part of Ameritech

Ameritech

AT&T Teleholdings, Inc., formerly known as Ameritech Corporation , was a U.S. telecommunications company that arose out of the 1984 AT&T divestiture. Ameritech was one of the seven Regional Bell Operating Companies that was created following the breakup of the Bell System...

, one of the 7 original Regional Bell Operating Companies. The Illinois Bell name continued to be used until January 1993, when Ameritech dropped all of their individual Bell Operating Company names in favor of using their corporate name, Ameritech, for marketing purposes.

In 1998, Ameritech announced intentions to merge with SBC, another former RBOC. Though the merger wasn't well received at first, it was allowed to occur with some conditions. The two companies were officially merged as of October 8, 1999. The Ameritech name continued to be used until 2002, despite the merger.

In 2002, SBC dropped the Ameritech name in favor of "SBC" as a national brand. On January 1, 2003, Illinois Bell, for regulatory business, was renamed Illinois Bell Telephone Company d/b/a SBC Illinois. Illinois Bell's legal name was changed once again in 2006, following conclusion of SBC Communications' purchase of AT&T

AT&T

AT&T Inc. is an American multinational telecommunications corporation headquartered in Whitacre Tower, Dallas, Texas, United States. It is the largest provider of mobile telephony and fixed telephony in the United States, and is also a provider of broadband and subscription television services...

, to Illinois Bell Telephone Company d/b/a AT&T Illinois.

Illinois Bell, in 1971, became the first ever telephone company to offer Call waiting

Call waiting

Call waiting , in telephony, is a feature on some telephone networks. If a calling party places a call to a called party which is otherwise engaged, and the called party has the call waiting feature enabled, the called party is able to suspend the current telephone call and switch to the new...

, Three-way calling, Speed Calling

Speed dial

Speed dial is a function available on many telephone systems allowing the user to place a call by pressing a reduced number of keys. This function is particularly useful for phone users who dial certain numbers on a regular basis....

, and Call forwarding

Call forwarding

Call forwarding , in telephony, is a feature on some telephone networks allowing an incoming call to a called party to be redirected to a third party. For example, the third party may be a mobile telephone, voicemail box or other telephone number where the desired called party is situated. It was...

, all popular local exchange carrier

Local exchange carrier

Local Exchange Carrier is a regulatory term in telecommunications for the local telephone company.In the United States, wireline telephone companies are divided into two large categories: long distance and local...

 telephone service options to this day.

Logos

	Illinois Bell Telephone Co. In 1920, Illinois Bell Telephone is formed, and it receives its own Bell logo. The logo contains "Illinois Bell Telephone Co.", along with the standard "American Telephone & Telegraph Co." This particular logo is used until 1939.
	Illinois Bell In 1969, AT&T revamped its corporate identity, resulting in a simplified Bell logo, absent of "Bell System". This logo will remain with IBT until 1983; "An Ameritech Ameritech AT&T Teleholdings, Inc., formerly known as Ameritech Corporation , was a U.S. telecommunications company that arose out of the 1984 AT&T divestiture. Ameritech was one of the seven Regional Bell Operating Companies that was created following the breakup of the Bell System...  Company" conjoined the logo in 1984.
	Ameritech Illinois In 1993, Ameritech chooses to do business as one "Ameritech", and drops the names of its Bells in advertising, and comes with a new logo. This logo remains until 2001.
	SBC Global Network In 1999, SBC acquires Ameritech. Shortly after, SBC begins attaching "SBC Global Network" to the ends of its subsidiary logos, resulting in this logo.
	SBC Ameritech Illinois In 2001, SBC proceeds to "unify" its companies by adding the "SBC" corporate logo to the operating company logos, and begins advertising Ameritech Illinois as "SBC Ameritech Illinois".
	SBC Illinois SBC eventually drops the names of all of its Bells in late 2002, and adds the title "d/b/a Doing business as The phrase "doing business as" is a legal term used in the United States, meaning that the trade name, or fictitious business name, under which the business or operation is conducted and presented to the world is not the legal name of the legal person who actually own it and are responsible for it...  SBC (name of state or region)" to the official names of its companies on January 1, 2003. Illinois Bell's d/b/a name becomes "SBC Illinois". SBC, later AT&T, retains "SBC Ameritech" on cards on its payphones, in order to better separate its operating regions.
	AT&T Illinois In 2005, SBC completed its acquisition of AT&T Corp., forming AT&T, Inc. AT&T changes the d/b/a names of its Bell Operating Companies on January 1, 2006, resulting in "AT&T Illinois".

External links

• Vintage advertising bookmarks of the Illinois Bell Telephone Co.