By Edgar B. Herwick III – July 3, 2015
We all have one, we know it by heart, and we share it with our neighbors. But chances are you haven’t thought that much about one ubiquitous part of American life — the ZIP Code.

We all know about the middle-class and suburban boom in the U.S. following World War II, but as the Postal Service’s Maureen Marion explains, that wasn’t the only thing booming.

“Not only boomtime for growth but boomtimes for volume of mail that was coming forward,” Marion said.

Advertising, business mail, postcards, you name it. From 10 billion in 1933 to 20 billion in ‘44 to 30 billion in ‘56. A promo video from the era tells the tale: “Literally, the post office stands to be swamped, overwhelmed, drowned in a sea of mail.”

The postal services needed a fix. In the ’40s, some large metro areas, like Boston, started to divide their mail delivery into zones, each represented by a two-digit number, Mike Powers, who runs the Greater Boston postal district, explains.

“It was called the Postal District Code, so it’d be Boston, 21, Massachusetts and that would highlight the area,” Powers said.

But the system wasn’t universal, and it quickly proved inadequate. So they scaled it up, launching the Zone Improvement Plan — an elegant, ultimately simple system known by the serendipitous acronym, ZIP. The first of five digits indicates one of nine regions of the country.

“The zero represents Massachusetts, Vermont … one is Delaware, Pennsylvania … all the way over to nine which is California,” Powers said.

The next two numbers represent which sectional center the mail goes to.

“Springfield area is 010, 011 is Berkshires, then you work east so 012, 13, … 025 and 026 are the Cape and Islands,” he said.

The last two are essentially your town or local post office.

ZIP has proved incredibly resilient. In 1983, the postal service got even more specific, with ZIP plus four. But thanks to technology, you don’t need even need to know the plus four.

“Technology today is remarkable,” Powers said. “Technology will read the mail piece, reads the address and actually assigns that four-digit add-on to the mail piece and sprays the appropriate bar code onto the mail piece and its actually the bar code that allows us to process and sort the mail so we can present it to our carriers in walk sequence.”

It’s hard to imagine now given its success, but when the ZIP code was first launched in July of 1963, it wasn’t mandatory, and it wasn’t immediately embraced. So a full-fledged marketing blitz was unleashed, complete with a mascot, Mr. ZIP.

More/Source: ZIP Codes Tamed The Postal Service Boom 52 Years Ago | WGBH News