GTE Corporation, formerly General Telephone & Electronics Corporation (1955–1982), was the largest independent telephone company in the United States during the days of the Bell System. The company operated from 1926, with roots tracing further back than that, until 2000, when it was acquired by Bell Atlantic, which changed its name to Verizon.
Regional Bell Operating Company (RBOC) was a corporate entity created as result of the antitrust lawsuit by the U.S. Department of Justice against the American Telephone and Telegraph Company (AT&T) in 1974 and settled in the Modification of Final Judgment on January 8, 1982.
AT&T Teleholdings, Inc., formerly known as Ameritech Corporation, was an American telecommunications company that arose out of the 1984 AT&T divestiture. Ameritech was one of the seven Regional Bell Operating Companies created following the breakup of the Bell System. Ameritech was acquired in 1999 by SBC Communications, which subsequently acquired AT&T Corporation in 2006, becoming the present-day AT&T.
The Pacific Bell Telephone Company (Pac Bell) is a telephone company that provides telephone service in California. The company is owned by AT&T through AT&T Teleholdings, and, though separate, is now marketed as “AT&T”. The company has been known by a number of names during which its service area has changed. The formal name of the company from the 1910s through the 1984 Bell System divestiture was The Pacific Telephone and Telegraph Company. The “Pacific Bell” was phased out of public use in 2002, although it remains the legal name of AT&T's local operating company in California and is still the holder of record for the infrastructure of cables and fiber through much of California.
Pacific Telesis Group (PacTel) was one of the seven Regional Bell Operating Companies, sometimes also referred to as "RBOCs" or "Baby Bells", created in 1983 in preparation of the breakup of AT&T Corporation. Pacific Telesis was the holding company for Pacific Bell, Nevada Bell, Pacific Telesis International, PacTel Mobile Services and PacTel InfoSystems. Pacific Telesis was headquartered in San Francisco and incorporated in Nevada. It was acquired by SBC Communications in 1997, which would eventually become today's AT&T Inc.
Cincinnati Bell, Inc., doing business as Altafiber, is a regional telecommunications service provider based in Cincinnati, Ohio, United States. It provides landline telephone, fiber-optic Internet, and IPTV services through its subsidiaries Altafiber Home Phone and Hawaiian Telcom, which are the incumbent local exchange carriers for the Greater Cincinnati metropolitan area and Hawaii. Other subsidiaries provide enterprise information technology services and long distance calling.
The monopoly position of the Bell System in the U.S. was ended on January 8, 1982. AT&T Corporation proposed by in a consent decree to relinquish control of the Bell Operating Companies, which had provided local telephone service in the United States. AT&T would continue to be a provider of long-distance service, while the now-independent Regional Bell Operating Companies (RBOCs), nicknamed the "Baby Bells", would provide local service, and would no longer be directly supplied with equipment from AT&T subsidiary Western Electric.
Michigan Bell is the subsidiary of AT&T serving the state of Michigan. Following the Bell System divestiture on January 8, 1984, the company became a subsidiary of Ameritech, the Regional Bell operating company that served the midwestern United States. Ameritech was subsequently acquired by SBC Communications, which later changed its name to AT&T.
Illinois Bell Telephone Company, LLC is the Bell Operating Company serving Illinois. It is owned by AT&T through AT&T Teleholdings, formerly Ameritech.
The Ohio Bell Telephone Company, now doing business as AT&T Ohio, is the Bell Operating Company serving most of Ohio and parts of West Virginia. It is a wholly owned subsidiary of AT&T.
Indiana Bell Telephone Company, Incorporated, is the Bell Operating Company serving Indiana. It is an indirect subsidiary of AT&T Inc., owned by AT&T Teleholdings.
Qwest Corporation, doing business as CenturyLink QC, is a Regional Bell Operating Company owned by Lumen Technologies. It was originally named Mountain States Telephone and Telegraph Company, later becoming known as Mountain Bell, then US West Communications, Inc. from 1991 to 2000. It includes the former operations of Malheur Bell, Northwestern Bell and Pacific Northwest Bell as well.
YP Texas Region Yellow Pages LLC is a division of YP Holdings that publishes telephone directories to Southwestern Bell customers for AT&T.
Dex One Corporation was an American marketing company providing online, mobile and print search marketing via their DexKnows.com website, print yellow pages directories and pay-per-click ad networks in the U.S.
SBC Telecom, Inc. d/b/a AT&T Small Business is a CLEC owned by AT&T that offers local telephone service outside the AT&T Bell Operating Company regions. It was formed in 1999 following provisions that required SBC Communications to offer telephone service outside its boundaries in order to get approval to merge with Ameritech.
The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company (AT&T), that dominated the telephone services industry in North America for over 100 years from its creation in 1877 until its antitrust breakup in 1983. The system of companies was often colloquially called Ma Bell, as it held a vertical monopoly over telecommunication products and services in most areas of the United States and Canada. At the time of the breakup of the Bell System in the early 1980s, it had assets of $150 billion and employed over one million people.
AT&T Corporation, an abbreviation for its former name, the American Telephone and Telegraph Company, was an American telecommunications company that provided voice, video, data, and Internet telecommunications and professional services to businesses, consumers, and government agencies.
Southwestern Bell Telephone Company, LLC is a wholly owned subsidiary of AT&T. It does business as other d.b.a. names in its operating region, which includes Arkansas, Kansas, Missouri, Oklahoma, Texas, and portions of Illinois. The company is currently headquartered in Dallas, Texas at One AT&T Plaza.
CenturyTel of the Midwest-Kendall, LLC is one of the CenturyLink operating companies in Wisconsin. The company's cities include Peshtigo, Kendall, and Marinette.
AT&T Communications, Inc. was a division of the AT&T Corporation that, through 23 subsidiaries, provided interexchange carrier and long-distance telephone services.
