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 ...

Mr. Zip, a gangly cartoonish figure with wide friendly eyes and a neat blue mail carrier's uniform, emerged fifty years ago to help the U.S. Postal Service promote its newest idea: five numbers added ...

Nowadays, people don't send letters to one another when they want to catch up. You may get holiday or birthday cards from your parents, grandparents or other family members and friends, but for the ...

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 ...