ZIP codes are a system of postal codes used by the United States Postal Service.
The term ZIP, an acronym for Zone Improvement Plan, is properly written in capital letters and was chosen to suggest that mail travels more efficiently, and therefore more quickly, when senders use the code in the postal address.
The term ZIP code was originally registered as a servicemark (a type of trademark) by the U.S. Postal Service, but its registration has since expired.
On July 1, 1963, non-mandatory ZIP codes were announced for the entire United States with the first Directory of Post Offices.
Simultaneously with the introduction of the ZIP code, two-letter state abbreviations were introduced.
Robert Aurand Moon, aka “Mr. Zip”
Robert Moon, an employee of the post office, is considered the father of the ZIP code.
Robert Aurand Moon was born April 15, 1917 in Williamsport, Pennsylvania.
He went on to become a postal inspector in Philadelphia.
Robert submitted his zip code proposal in 1944.
The post office gives credit to Robert Moon for only the first three digits of the ZIP code, which describe the sectional center facility (SCF) or “sec center.”
An SCF is a central mail processing facility with those three digits. The SCF sorts mail to all post offices with those first three digits in their ZIP codes. The mail is sorted according to the final two digits of the ZIP code and sent to the corresponding post offices in the early morning.
Sectional centers do not deliver mail and are not open to the public (though the building may include a post office open to the public), and most of the workers are employed to work night shift.
Mail picked up at post offices is sent to their own SCF in the afternoon, where the mail is sorted overnight.
In 1967, these were made mandatory for second- and third-class bulk mailers, and the system was soon adopted generally. The United States Post Office used a cartoon character, whom it called Mr. ZIP, to promote use of the ZIP code. He was often depicted with a legend such as “USE ZIP CODE” in the selvage of panes of stamps or on labels contained in, or the covers of, booklet panes of stamps.
Robert Moon died April 11, 2001, in Leesburg, Florida.
Now WE know em