Catalysts of Change

In addition to advances in mechanized and automated machinery, there have been a number of developments through history that have had extraordinary impacts on how mail is processed. A selection of five of these “Catalysts of Change” are found below.

The first and second postage stamps, issued in 1847
Benjamin Franklin 5-cent and George Washington 10-cent, 1847 postage stamps

Until 1847, local postmasters calculated the cost of postage, which varied depending on the number of sheets in the letter and its destination. The sender could pay all, part, or none of the postage. The addressee had to make up the difference.

In 1845, Congress lowered postal rates and made them more uniform. Two years later, Congress authorized the first postage stamp. Rates dropped again in 1851—down to 3 cents—where they remained for more than 30 years.

Who was on the first postage stamps?
The first two U.S. postage stamps were a 5-cent stamp showing Benjamin Franklin and a 10-cent stamp with the image of George Washington, both issued in 1847. In 1855, Post Office made the use of prepaid postage stamps mandatory for mailing letters.

How did lower postage rates affect ordinary citizens?
Lower rates and prepaid postage stamps brought the cost of sending first-class mail within reach of many more Americans. This encouraged more reading and writing, letters to distant friends and relatives, business transactions, and communication of many kinds across the growing United States.

Mr. Zip
Mr. Zip was the key figure of the ZIP Code advertising campaign.

By the early 1960s, the swelling volume of mail was taxing the Post Office Department to its limits. Zoning Improvement Plan—ZIP—Codes were one response to this growing mountain of mail. Using numbers to stand for regions, cities, post offices, or even city neighborhoods made it easier sort the mail—by machine or by hand. Today ZIP codes are used to help shape everything from voting districts to marketing campaigns.

What Do the Codes Represent?
Think of each 5-digit ZIP Code as a group of addresses. They might be homes or businesses, schools or apartment houses. One 5-digit number might represent 10,000 delivery points—spread out over many miles in a rural area or concentrated in a few city blocks.

What Does Each Number Mean?
The first digit represents a region of the country. The next two digits stand for a central post office facility in the region. The last two digits represent a post office or a postal zone. So, the ZIP Code 97403 means the west coast & Pacific, Eugene mail center, and the University of Oregon.

Image of a bar code
These bars represent a ZIP Code.

Once numbers—ZIP Codes—began to represent addresses, barcodes representing numbers was the next step. Barcodes are easily read by machines all along the path of a letter or parcel. From the start, they helped mail reach its destination faster and more accurately. Today, they help generate information for senders and recipients as mail moves across the country.

How do bars represent ZIP Codes?
The USPS began using barcodes in 1982. The bars represented the 5 digits of the ZIP Code, and helped automate mail sorting—the machines read the stripes instead of the numbers.

What’s in a barcode besides the ZIP Code?
Over the years, the USPS has used 5, 6, 9, and now 11-digit barcodes to steadily increase the speed and accuracy of mail delivery. The extra bars include “carrier sort” level coding that sorts the mail to the order it’s delivered in.

Think you can decipher a barcode? Try this:

Decode the Barcode »

OCR Camera Mechanism
OCR Camera Mechanism

By 1997, Optical Character Recognition (OCR) software could recognize handwritten block letters and translate them into code, then double-check the address against a database of known addresses and names.

Of course, some handwriting is so bad that it challenges even the best machines. Workers read and decipher scanned images of these handwritten addresses. Then they return that information to automated machinery that applies the appropriate routing barcode and moves the mail piece back into the mail stream.

Automation-readable barcode
Automation-readable barcode

Once ZIP Codes were translated into automation-readable barcodes, the USPS and mailing companies began working to pack more and more information into those codes. The codes evolved into the USPS’s Intelligent Mail Barcode system. The original 5-digit ZIP code is now 31-digits of information tucked into 65 bars in each code.

The 31 digits include ZIP Code information other data that can reveal how the mail was presorted, whether it is first-class mail or a periodical, the business sending each piece, and automatic address forwarding information.

The barcode also permits tracking of individual pieces of mail. When you return a pre-addressed business reply by mail, businesses can forecast when it will arrive. All this saves companies money, makes their business more predictable, speeds mail delivery time, and makes the postal system even more efficient—and efficiency is important, considering that half a billion pieces of mail flow through the system each day.

Systems at Work