How zip codes helped organize America


Between 1940 and 1960, the amount of mail doubled in The United States. That’s largely because companies began using computers to send automated mailings. Soon, the flood of mail sent by banks, advertisers, and other businesses was overwhelming postal workers. The Postal Service needed a solution. In 1963, the Zone Improvement Plan divided the country into ten regions and assigned five digits increasing in specificity, from region, to large sorting centers, to smaller post offices. Where previously mail workers had to figure out which post office went with which address, now the zip code provided that information for them. The government promoted the new system with a cartoon character, Mr. ZIP, and a song from a zip-code lovin’ band called The Swingin’ Six. You know you’ve gotta have a zip code on the envelope, a zip code so you won’t just have to hope.

A zip code morning, noon and night, and everything will be alright. And it worked — by 1969, 83% of Americans were using zip codes, and between 1971 and 1980, the number of pieces of mail that were processed per year, increased by 17 billion. But the system was limited. Zip codes are made from digits, unlike the alphanumeric Canadian system, which can encode more information per character. As America grew, zip codes got longer. In 1983, a four digit suffix was added to denote specific addresses like city blocks or large buildings. While this update improved delivery, it requires zip codes to be continually managed to reflect changing destinations and delivery routes. Instead of a system dependent on structures, a geocoded zip code would be dependent on place.

This gives every point on earth a unique permanent address. And geocoded deliveries can be sent to specific pick-up points at an address. More specificity would also benefit industries that use zip codes for purposes other than sending mail, like analyzing data. In Britain, the postal service has already geocoded their system and London realtors have used that data to make more detailed maps of housing prices. Without geocodes, American addressing is limited to zip codes and building numbers. Any further detail has to be written. With a geocode, sending mail directly to The Oval Office is as easy as remembering 38.8973603,-77.0374162. Or not that easy. Complex numbers hard to remember, so systems have been created to simplify geocodes.

One system called Natural Area Code, converts latitudes and longitudes into alphanumeric “NAC” tags. Which is netter, but still not great. A different system uses words, which we tend to remember more easily than characters. A company called What3words has divided the world into 57 trillion squares, and given each square a unique string of three words. Each combination of words goes with a specific latitude and longitude. If our postal service used What3Words, you could send your letter to “rich.soup.noble”, and the President could pick it up at the window of the Oval Office. While language makes geocodes easier for humans, machines prefer to process numbers. So the zip code will probably evolve in ways we won’t notice. Right now, computers add delivery instructions by converting zip codes into a barcode that is printed on a shipment. In the future, a similar process might incorporate geocoding, which would leave us with one question: If we don’t need to learn a new system, do we still get to a new song? We’ve told you everything we know. It’s up to you to make zip code go.