On July 1, 1963, the U.S. Post Office Department introduced the ZIP code program to get a handle on the heaping surplus of mail. Today, those five digits represent much more for American society. Back ...

One of the most important breakthroughs in modern communication lies in an overlooked place. It’s printed onto envelopes, just below the address. Although we think nothing of the ZIP Code these days, ...

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 this ubiquitous part of American life — the ZIP code. We all know about ...

The House passed two bills Monday night that would authorize the U.S. Postal Service to create 76 new ZIP codes for communities nationwide. This is not the first proposed ZIP code upgrade. In December ...

The humble ZIP Code shows up in all kinds of surprising places. Planet Money looks at how it was born, how it transformed the mail and talks to one researcher who argues that it's gone too far. The ...

Postmaster General J. Edward Day, left, and two city letter carriers posing with Mr. Zip in 1963. (N/A/United States Postal Service.) Perspective by John Kelly While vacationing at his Texas ranch in ...