Telephone companies

 Telephone companies

https://en.wikipedia.org/wiki/Pacific_Bell

https://en.wikipedia.org/wiki/Southwestern_Bell

SBC Communications (formerly Southwestern Bell Corporation) was a "Baby Bell" holding company that grew to own several major regional Bell operating companies before acquiring its former parent, AT&T Corp., in 2005 to form the modern AT&T Inc.. Key telephone companies under the SBC umbrella included Southwestern Bell, Pacific Telesis (Pacific Bell/Nevada Bell), Ameritech, and SNET.

https://www.att.com/