AT&T
- AT&T 1872 - 1983
- - Invention
- - Reis, Meucci, Gray
- - Patent Era
- - Telephone
- AT&T 1894 - 1921
- - Dual Service Era
- - Kingsbury C
- - Willis Graham Act
- - World War I
- - Unions
- AT&T 1922 - 1948
- - Comm Act of 1934
- AT&T 1949 - 1962
- - 1956 Consent Decree
- AT&T 1963 - 1984
- - Carterfone
- - Computer Inquiries
- - 1984 Divestiture
- AT&T Post Divestiture
- - Telecom Act of 96
- - AT&T Cable Broadband
- - Mergers
- - DataCaps
- - Interconnection
- - VoIP