Setting Automatic Dials on Keystone Telephones - 1921 - 16th and Summer Streets

Public Ledger 24 Jan 1924

Automatic rotary dials using various exchange prefixes per finger hole via exchanges around the tri-state area was the reason that Keystone Telephone in the Philadelphia area was the preferred business to business telephone over that of the operators at AT&T that connected calls in the early days of the twentieth century and the reason many Philly businesses had two phone companies up until 1945 when AT&T bought out Keystone. 


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