When were Zip Codes added to our addresses' by the USPS?
Zip Codes went into effect in the USA in 1963 in order to fasten delivery of mail. ZIP stands for Zone Improvement Plan. This plan was devised by the Post Office Department and worked out well. Most businesses had automated mailing systems was able to easily handle the 5 digits that would allow mailings to bypass as many as six mail-handling steps.
Trying to encourage people to use ZIP codes, the Post Office Department ran a wide promotional campaign. This is an example of one of the earliest advertisements with a popular character Mr. Zip, created for the campaign.