Why did a dial phone have letters on?

Answer 1

for a long period (when I was a boy), phone numbers consisted of a word plus a number (Pennsylvania 6-5000 was turned into a song)

so it would be easier to memorize.

Added: Thus Pennsylvania 6 would be PA6 or 726-5000. I am from Ohio and our number was BA8 XXXX or 228. People all around the country had similar numbers.

Answer 2

In the earliest days of the telephone, customers could not dial their own calls. They had to signal the operator (in some cases, just by lifting the receiver; in other cases, by turning a crank handle) and tell the operator the number they wanted to reach. In large and even medium-sized cities, there were multiple exchanges, each serving perhaps a few thousand customers. Your telephone number was the name of your exchange, followed by a number within that exchange; for example, Riverside 1234 or Diamond 123.

In order to allow for customer dialing, even of local calls, there had to be a way to convert the exchange name to a number, so the letters were mapped to the numbers, and the first two or three letters of the exchange name were converted. Thus, the Riverside exchange might be numbers beginning with 748, or just 74.

Later, even after the great majority of local calls were direct-dialed by the customer, exchange names provided a mnemonic (memory aid), as many people found it easier to remember, for example, LAndmark 7 instead of 527. The listings in the telephone directory eventually shifted to LA7-xxxx, and finally to 527-xxxx.

Answer 3

It was introduced with advertizing and message keeping. It makes it easier to remember the number you called because it allows you to just remember a name.

Answer 4

Because telephone numbers used to be given with letters, normally three letters and then numbers. The letters spelled an abbreviation for the Exchange name.