Philadelphia city telephone exchanges

Philadelphia was unique among major American cities in having both a Bell System company (officially, during most of the era in question, named The Bell Telephone Company of Pennsylvania, or Bell of Pennsylvania for short) and an independent company, the Keystone Telephone Company, until September 17, 1945. This site will cover both Bell and Keystone, but because Keystone was a rather small company with only 7 exchanges, the larger portion will be devoted to Bell exchanges. Like all telephone systems, the Philadelphia companies were manual in the early days. And like most major cities, when dial telephones were initially started, there was an early pattern, different from the two-letter one-digit exchange and four-digit line number that became standard in the 1950s. The Bell company serving Philadelphia was one of four cities (the others being New York City, Chicago, and Boston), where the early dial pattern was three letters for the exchange and four digits for the line number. ( Keystone, being much smaller, used a different pattern, with a single digit associated with each exchange, and the names being shown on the dial.)

So the history of the telephone exchange names used by Bell of Pennsylvania in Philadelphia, similarly to the history of the telephone exchange names in New York City, can be divided into three periods:

1. The pre-dial period, when all telephone calls were completed by manual action by operators, and there were no constraints on exchange names other than that there was no likelihood of confusion when a customer gave the name to the operator,
2. The early dial period, in which the directory format was set up to accommodate dialing the first three letters of an exchange name followed by a four-digit number designating the individual line, though in fact not all exchanges provided for dialing by the phones in those exchanges, and
3. The late dial period, beginning (in Philadelphia) on July 5, 1946, in which, instead of the first three letters of an exchange name, one dialed only the first two letters and an "office number", again followed by four digits designating the individual line.

Information on the pre-dial era has not yet been acquired. This site, therefore, provides data only on the two later periods.

Last modified March 3, 2009.