Coxsackie Antique Center

Where Yesterday Meets Tomorrow

Breaking the Code

Zip codes, area codes, printer codes, and postal zones.

We went into an antique center in Cooperstown the other day and saw a nice catalog of mechanics tools. The price tag said "about 1930 $38.00." That's a pretty high but not totally absurd price for a 1930 tool catalog in mint condition. Perhaps, I thought, the dealer could be talked down to a more realistic price. I looked the catalog over very carefully. The first thing I saw was that the company address was Los Angeles 54, Calif. On the back cover, printed in very small type, was a small code number "5225m." I put the catalog back and walked away. It was worth maybe $10.00.

Postal zones were first used on May 1, 1943 (e.g., Los Angeles 54 or New York 16.) All large and many medium sized cities had zones. If a zone is listed you know your item dates after 1943. If no zone is listed the item might pre-date 1943. Small towns never used zones so the lack of zone means nothing. All large cities did use zones, so if the item contains a full address of a large city without a zone, the item pre-dates 1943. Unfortunately, manufacturers did not always print their full mailing address on their items. They often thought that Brooklyn NY or St. Louis Mo. was a sufficient cachet so lack of a zone could simply mean the manufacturer didn't bother to print it. Here's a research project for someone. Which cities had zones and which one's didn't? The answer can be found in the official Postal Handbooks from the 1940s and 50s (which would make a fine addition to our Center reference library!)

Zip codes replaced postal zones on July 1, 1963. All post offices, no matter how small, were assigned zip codes. So, if an item has a zip code, you know it was made after 1963. In some areas, postal zones continued to be used for some time after 1963. We have some 1965 Antiques Dealer magazines in the reference library with ads that cite postal zones rather than zip codes. But the 1963 date is a pretty good rule of thumb.

Incidently, 1963 is about 5 years after the mid 1950s ended so we would not expect to find zip codes on items offered for sale at the center.

A final postal clue. The use of the two character capitalized state codes is a development of the Computer Age. The codes were adopted by the Post Office in 1963 along with zip codes but were not widely used until computerized mailing lists became common. If the address is Los Angeles CA or Phoenix AZ you're almost certainly looking at an item from the 70s or later. Of course some states, like NY or NC or NJ or SD, were always abbreviated with two character caps, but states like Calif., Ariz., Mass., or Conn. were usually abbreviated more expansively. So here's another good research project. When did the two character state codes come into general use?

The use of a 3 digit area code in phone numbers (such as 518-731-8888) began on November 10, 1951. The system spread very gradually so inclusion of an area code will date the item after 1951, but not printing it will not date the item as pre-1951. The use of exchanges (such as BU3-5554) gradually faded out during the 1960s. The increase in the number of digits in a phone number also occurred gradually over several decades with rural areas retaining smaller digit numbers much longer than urban ones. Dating clues from phone numbers would be a fascinating and very valuable research project for some energetic researcher.

And back to the tool catalog. Companies often put codes on their advertising brochures so that they can later tell when they were printed and how many copies they've used up. The codes usually include the last two digits for the year and often the date and month too. They will also include the print run size followed by an "m" to indicate thousands. Thus a code "45-2-19-50m" would mean the item was printed on Feb 19, 1945 and that 50,000 copies were printed. So "5225m" probably means that in 1952 the company printed 25,000 copies of the catalog!

From such arcana are the dates of antiques gleaned.


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