The Zip Code Turns 50

It was fifty years ago today that the US Postal Service introduced the mandatory Zip Code. The term Zip Code really in and acronym for Zone Improvement Plan. It was masterminded by Robert Moon who worked as a postal inspector in Philadelphia. Moon came up with the plan in the late 1940's and it was under study for many years until in 1963 it was made mandatory. The first number identifies an area of the county the next numbers are cities and the last numbers indicate an area within a city.
In the 1980's another four digits were added to the number but these honestly mean almost nothing to the average user.