Area Code History
When did area codes first come into use?
The area code system was developed by AT&T and Bell Laboratories in the 1940's, and went into effect in 1947. It was called the North American Numbering Plan (NANP) and included the United States and Canada .
How were the original area codes distributed?
In 1947, states and provinces that had a single area code we assigned three digit codes with 0 as the middle number, such as 203 for Connecticut and 305 for Florida . There were 86 area codes at that time.
States and provinces that had more than one area code distributed to them were given three digit codes with 1 as the middle number, such as 916 and 213 for various sections of California , and 212 and 518 for various sections of New York .
The first and third digits were allotted according to population density in the city or region the area code was going to, with the most populated areas getting the lowest numbers. The New York City area, for example, was assigned 212, while the surrounding suburbs were assigned 914.
The rationale for this “low number/high population” scheme was based on the fact that phones had rotary dials in those days. Lower numbers resulted in shorter “dial pulls” so it was reasoned that the regions with the most people in them should require the least “work” to call.
An interesting theory. I have never analyzed if big cities https://populationstat.com/australia/sydney have some special coding. But having checked codes of a few megalopolises I see that it is very far from being true. Each city has its own system and a variety of codes. And they always consisted of all possible figures. You may check it in a number of resources. Being heavily populated, cities cannot use only a few figures for so many districts.