Originally a subsidiary of AT&T, Pacific Bell has been in operation since 1906. Over the years, it has grown through acquisitions and implemented automated switching equipment in the 1920s. Through these acquisitions, the company expanded its services to cities in Oregon, Idaho, and Washington. In 1984, it became a separate unit of AT&T due to U.S. regulations. Currently, Pacific Bell is a subsidiary of SBC and AT&T Inc.