It’s one of the more intriguing zip codes in the country: 43210. Is it a countdown of sorts, often used in marketing campaigns? Or are the numbers a coincidental anomaly, with logic and reason being the contributing factor behind the numbers?

43210 is the zip code for Ohio State University’s post office, and one WOSU listener asked the Curious Cbus project to answer how the university got this easy-to-remember identifier.

Turns out, it is a coincidence. It wasn’t chosen for fun, or because it’s a countdown. There is actually an extremely formulaic system to how it came to be.

First, a quick history on zip codes.

The ZIP Code was introduced by the United States Postal Service in 1963, with ZIP standing for Zone Improvement Plan.

Many cities in the United States had zone codes, two-digit codes that correlated to different parts of the cities. Zone codes were first introduced in 1943.

However, to a tired-eyed mail sorter, Birmingham 11 and Burlington 11 probably looked a little too similar. Maybe handwriting wasn’t the best. There clearly needed to be a better system.

Removing the necessity of city and state on envelopes and packages, and leaving it to a formulaic five-digit zip code improved accuracy of mail sorting, and quite frankly, greatly improved the speed of delivery.

Now, onto how the Ohio State University post office was assigned the almost-mesmerizing 43210 zip.

Let’s break down the zip code digit by digit, starting with the 4.

The first digit in the zip code is a regional number. These numbers are assigned from 0-9 spreading East to West. The 4 was assigned to Ohio, Kentucky, Michigan and Indiana. All Maine zip codes start with 0. All California zip codes start with 9.

Cities and regions in Ohio were then assigned a two-number codes, the first digit being either the 3, 4 or 5. And the second digit assigned randomly. Columbus was assigned 32.

The last two digits are where the zone codes come into play.

Back before ZIP Codes, each post office in Columbus was given a zone code. Grandview’s zone code was 12, downtown was 15, Clintonville was 02, Obetz area was 07, University District was 01. And the zone code for Ohio State’s post office was 10.

Put it together: 4 is for Ohio. 32 is for Columbus. 10 is for the zone code of the university.

43210.

Got your own question about Ohio State or Columbus? Ask Curious Cbus below and we may answer it in a future story.

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