US Postal Code History
The implementation of the postal system in the United States was an incredibly innovative invention that revolutionized communication in the nineteenth century, before the telegraph began to change the world and make it a little bit smaller. However, on aspect of the postal system that did not come until nearly halfway into the twentieth century was the postal, or zip code. In 1943, the postal service implemented the zip code but it looked very different. For example, it only consisted of a couple of letters, 16 for example in Minneapolis, and it represented the postal zone in that particular city.

Things began to change in the 1960s when the postal service implemented the zip code. Implemented on July 1, 1963, it was a non mandatory code that would be used throughout the country. Despite being implemented in 1963, it was Robert Moon, the father of the zip code and a postal employee, who submitted his proposal for the zip code in 1944, while working as a postal inspector. However, he only came up with the first three digits of the postal code, which describes the central mail processing facility The central mail processing facility sorts mail to all the post offices using those first three digits, then mail is sorted according to the last two digits of the zip code, with the mail being sent to the post offices they need to go to that morning. The last two digits of the zip code still correspond with the city like they did in 1943. For example, Minneapolis is 55416, with 16 being the original code for that zone of the city. By 1967, the zip code was mandatory for all second and third class bulk mailers and the system had been adopted for the most part by everyone else. In an effort to promote the zip code to everyone, Mr. ZIP was created. His creation was an effort on the part of the postal service to get people using zip codes.

Due to a rising population in the United States, the postal service began using an expanded zip code, called ZIP plus 4, in 1983. This zip code had the usual five numbers, plus for add on numbers. The four extra numbers are used to identify a certain segment within the five digit delivery area, usually a city block or apartment building. Using the expanded zip code is not required, and most multiline optical character readers can figure out the code based on the other five digits in the zip code.
Nowadays, the zip code is often printed in bar code through an automated machine. This barcode can be printed by the person sending the mail, and can even be printed in Pre-2007 versions of Microsoft Word.
For those who send bulk mail, having a pre printed barcode can actually give them a discount, so many companies will often use this method to save on costs when they send out mail on a regular basis.

Conclusion
The zip code is a revolutionary invention that most people do not think about. It has allowed the postal service to speed up its delivery substantially. Now, thanks to the use of barcodes and other forms of technology that can read the zip code, even when it is written in using object character recognition software, the process to mail something has become faster than ever.
For the post office, it is important that they keep inventing new technology to speed up the process of mailing letters, packages and more, since they face so much competition from other avenues including email and courier companies who advertise their ability to send mail and packages much faster than the post office. The zip code is something that has become part of the fabric of our lives and for most of us, the only numbers we ever memorize in our lives are our phone number, social security number and our zip code. Hence, it has proven its importance enough to the point that we deem it worthy of remembering.