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 ...

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 ...

This post may contain links from our sponsors and affiliates, and Flywheel Publishing may receive compensation for actions taken through them. A letter without a ZIP code may not reach its intended ...