Sending and receiving mail is something that all of us have done throughout our lives. I remember being taught in school all of the essential steps. We would write the mailing address in the center of the envelope, the return address in the top left corner and finally affix a stamp in the top right corner before it was ready to send. It was the way I first really started to write out and memorize my home address as well. One item in those addresses that always intrigued me is a five- or nine-digit number that many people recognize but often don’t fully know the meaning of, ZIP Codes.
One of the earliest government agencies to be created after the establishment of the United States of America was the Post Office Department. Founded in 1792 during George Washington’s first term as President, it provided essential services for a young nation that had to rely on traveling by foot or horse to travel and communicate. Having a post office was considered so important at that time that “to establish Post Offices and Post Roads” is one of the original powers of Congress listed in Article I of the Constitution.
As the country grew so did the Post Office with it, delivering mail to all corners of the nation. Eventually, as more and more of the population began to live in cities and there were more addresses to deliver mail to, a new method was needed to deliver mail more efficiently. Thus, some local post offices began to divide their cities into postal zones with numbers added after each address on mail for faster sorting.
It wasn’t until the World War II era although, that this concept was applied nationwide. Robert Moon is the post official called the “Father of the ZIP Code” for creating the first three digits of the code that aligned with the designation of the sorting facility that served an area (such as 563 for St. Cloud). The next two digits were then added to further subdivide these areas(56301, 56302, etc.). These five digit ZIP Codes were then introduced in July of 1963, along with standard state abbreviations.
Before 1963 and ZIP Codes, state abbreviations like our much-used “MN” were not official and so the full state name or other abbreviations were often written out. In order to reduce the number of characters on the address line, ZIP Codes and the two letter state abbreviations were rolled out at the same time, and have been continued to the present day.
What about that additional four numbers given after the first five in a ZIP Code then? They were introduced as ZIP+4 in 1983 as a way to further specify. According to zip-codes.com, the sixth and seventh digits of the total ZIP Code refer to a delivery sector, such as several blocks. The eighth and ninth digits narrow this down even further to a delivery segment. This could be as specific as a side of a street or a floor of an office building. So while the last four numbers of a ZIP Code are not required, they do make for faster sorting of your mail or package when it is processed by the post office.
Now you have it. Those numbers on your address labels have a history rooted in the US Post Office and its history of delivering the mail in an efficient and orderly manner. It’s a mark of ingenuity and practicality that makes it much easier to distribute mail all across the country. So the next time you see that five to nine number sequence on your mail or package or have to remember it to send something, remember just how big a job these “little” ZIP Codes do.
Connor Kockler is a student at St. John’s University. He enjoys writing, politics, and news, among other interests.
