Hanna Horvath is a CERTIFIED FINANCIAL PLANNER™ and Red Venture's senior editor of content partnerships. Fox Money is a personal finance hub featuring content generated by Credible Operations, Inc.

The familiar five-digit number was part of a nationwide effort to modernize the mail.

Add Yahoo as a preferred source to see more of our stories on Google. Most Americans know their ZIP code by heart. They type it into online forms, scribble it on envelopes and memorize it as part of ...

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 ...