OnI Love Lucy , whenever Lucy or Ricky Ricardo gave out their phone number , they ’d say it as “ Murray Hill 5 - 9975 . ” Even though that may look and vocalise like gibberish to modern speech sound - substance abuser , it was perfectly normal at the fourth dimension . Lucy , you got some ‘ splaining to do .
earphone number look like this in the center of the 20th 100 because of telephone exchanges — the hubs through which an area ’s calls would be rout . sound contributor were given a unique five - digit act within their service area . These would be preceded by two digits , which were key byletters , that denote the telephone set substitution you were connect to . ( Before the fifties , some cities used three letter and four number , while others had two letters and three number . The two letter , five telephone number format — or “ 2L-5N”—was eventually standardize throughout the country ) .
Full words were used to help customers recollect the telephone exchange name , and because they were easy to understand , particularly for switchboard operator . Similar - sounding letters would cause confusion , so decided names or phrases were favour . The specific word used to key out the two - letter of the alphabet codes were n’t standardise , but rather recommended by AT&T / Bell in theirNotes on Nationwide Dialing , 1955[PDF ] , which was distribute around the country as multitude begin to make more and more long - distance call . you’re able to see the listing of gens for each telephone exchangehere .
Around this same time , arena codes were introduced , but they were used mostly by operators and not customers . In the late 1950s and throughout the next two decades , U.S. phone systems began switching to all - issue calling , which did n’t rely on primitive telephone exchanges and could exponentially add customer just by introducing novel area code .
The modification did n’t occur without some resistance , however . multitude loved the literary spell of their previous telephone exchange names , and grouping like the Anti - Digit Dialing League and the Committee of Ten Million to Oppose All - Number Calling were formed toprotest the switch .
unwarranted , proper ? citizenry in reality used to pick up the sound and make calls .
A version of this story run in 2015 ; it has been update for 2023 .
