How exactly did the area code come to be?

Despite the rise of the internet, the 10-digit telephone number remains an ubiquitous and all-encompassing method of communication. But it hasn’t been that long since human operators were responsible for completing telephone calls, and The Atlantic has put together a look at how the 10-digit number rose to prominence in the middle of the last century. Beyond the historical journey, the piece also digs deep into the cultural significance that area codes have taken on over the past decades.

In the mid-20th century, in response to the United States’ rapidly expanding telephone network, executives at the Bell System introduced a new way of dialing the phone. Until then, for the most part, it was human operators—mostly women—who had directed calls to their destinations. Dialing systems had reflected this reliance on the vocal cord. Phone numbers weren’t numbers; they were alphanumeric addresses, named after phone exchanges that encompassed particular geographic areas. The Elizabeth Taylor movie Butterfield 8 gets its name from that system: The Butterfield exchange served the tony establishments of Manhattan’s Upper East Side. Lucy and Ricky Ricardo, should you have attempted to call their apartment, were apparently reachable with a request for “Murray Hill 5-9975.”