Why aren numerically sequential area codes given to geographically adjacent areas?
The assignment of telephone area codes may seem random but actually it’s pretty sensible. The North American Numbering Plan, of which the area codes are a part, was worked out in the late 1940s to ensure standardized numbering nationwide, helping to make direct-dial long distance possible. (Prior to that time, one had to go through an operator, that is ‘trunk call’). On the rotary-dial phones then in use, dialing a nine (9) took a lot longer than dialing a one(1), which tied up expensive switching equipment. So AT&T assigned “low dial pull” numbers to the markets with the most telephones and thus presumably the highest number of incoming long-distance calls. New York got 212, Chicago 312, L.A 213, Detroit 313, Dallas 214 and so on. Strangely Washington D.C got 202 and Maryland 301 (Zero, remember, has the highest dial pull of all) may be this anomaly represented some “smoldering vendetta” against the Eastern Seaboard 🙂 Anyway. The issue of dial pulls became academic with the introduc
