Introduction
The Bell System was a system of telecommunication companies, led by the Bell Telephone Company and later by the American Telephone and Telegraph Company, 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 in "Mother 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 (equivalent to $460 billion in 2025) and employed over one million people.
Since the 1910s, American antitrust regulators had been observing and accusing the Bell System of abusing its monopoly power and had brought legal action multiple times. In 1974 the Antitrust Division of the U.S. Department of Justice brought a lawsuit against Bell claiming violations of the Sherman Antitrust Act. In 1982, anticipating that it could not win, AT&T agreed to a Justice Department-mandated consent decree that settled the lawsuit and ordered it to separate itself from its local phone companies, who would be broken up up into seven "Regional Bell Operating Companies" (known as the "Baby Bells"). This ended the existence of the conglomerate in 1984.
Following the breakup, the Baby Bells were independent companies and several of them became large corporations. However, many of these companies, as well the former parent company, later re-merged, and, as a result, by 2025 most of the assets and geographical service areas of the former Bell System were held by two Baby Bells descendants: AT&T and Verizon.
Document Library
We have around 40,000 documents relating to the Bell System including the Bell System Practices and more fully indexed and searchable:
Ameritech Technical Specifications
Ameritech Technical Specifications
AT&T Centrex Traffic Engineering Notes
AT&T Centrex Traffic Engineering Notes (TENs)
AT&T Specifications
AT&T Specifications from 1931 and earlier
AT&T Technical Publications (Post-Divestiture)
AT&T Technical Publications (Post-Divestiture)
Bellcomm Memoranda and Reports for NASA
Bellcomm Memoranda and Reports for NASA
BellSouth Technical Publications
BellSouth Technical Publications
Bell System Practices
A compilation of technical publications which describes the best methods of engineering, constructing, installing, and maintaining the telephone plant of the Bell System.
Bell System X-Specifications
Bell System X-Specifications
Circuit Descriptions
Bell System Circuit Descriptions (CDs and BTs)
Circuit Pack Schematics
Circuit Pack Schematics (CPS)
Dial Facilities Management Practices (DFMPs)
Distance Dialing Coordinating Handbooks
Distance Dialing Coordinating Handbooks
Equipment Drawings
Bell System Equipment Drawings (EDs)
Forms
Bell System Forms
Input and Output Manuals
Input and Output Manuals
J Specification Drawings
Bell System J Specification Drawings
Letters and Memos
Bell Systems Letters and Memos
Local Operating Practices
Local Operating Practices
Miscellaneous Drawings
Bell System Miscellaneous Drawings (A, B, BL, ES, ESL, ESO, L, LA, P, T, etc.)
MP Drawings
MP Drawings including Sequence Charts (SCs), Operational Sketches (OSs), and Reference Material (RMs)
Repair Specifications
Bell System Repair Specifications (BSRSs)
Routing Information Letters
AT&T Routing Information Letters
Schematic Drawings
Bell System Schematic Drawings (SDs)
Six-Digit Select Codes
AT&T documents with six-digit select codes.
Stored Program Control System Documents
Bell System Stored Program Control System (SPCS) Documents (PA, PG, PK, PR, etc.)
Technical Reference Publications
Bell System and AT&T Technical Reference Publications (TR PUBs)
US West / Qwest Technical Publications
US West / Qwest Technical Publications
Western Electric Installation Handbooks
Credits and Thanks
Many of the files within this section have been mirrored with permission from The Telecom Archive, thank you.
The introduction is from Wikipedia.