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Each year, some (US) ZIP codes change. New codes are added, preferred and acceptable city names change, codes are sometimes deleted, or even swapped between two cities.

Are there archives anywhere of ZIP code changes by year, going back to the 1970's and 1980's?

Are they perhaps listed in certain government or USPS publications? I've been unable to find anything other than current ZIP codes at the USPS site, and they don't seem to be mentioned in the USPS Federal Register filings. A dataset of all of the changes would be even better! Census data doesn't help as ZCTA's are only since 2000 (and are subtly different anyway).

The changes are usually announced in newspapers, like this Florida article from 1987 (with more in the "related articles" sidebar). Are the press releases that generate such articles archived? It appears that (in recent years at least) the changes are decided at the USPS district level, but those districts have themselves been split or (more usually) merged and re-arranged, so tracking down the changes at the district level is likely to be very difficult.

After further searching, it appears one place that some changes are listed is in the "address management" section of the Postal Bulletin when Post Offices are closed (and sometimes the associated zip code is retired). As the Postal Bulletin is issued every two weeks, and it's up to issue 22,385, going through the back issues would be a very lengthy process (and that section seems to only apply to Post Office closings, not new ZIP codes). The online archive only goes back to 2001.

Another source is the "National 5-digit Zip Code Directory", a large book (later two volumes) that has been issued by the USPS since 1965. A few have been scanned by Google Books, but none very early and none with full text available.

I need the list of changes (or snapshots of the zip code list) to find locations for some historical data that just has ZIP codes shown, going back 30-40 years. In other words, to put placenames (the name at that time) to the zip code (at that time). I don't need exact geographic co-ordinates.

Using the current preferred place name for a ZIP code will be right in many (most) cases (or, better, a list of the preferred and acceptable names). But there will be a percentage that have changed (split, merged, swapped), and where using a modern lookup for 1970's data will give incorrect (and misleading) results. It's those exceptions I want to deal with.

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I've never used data that old for addressing. One place I would start is with the US Census 1970. It used real zip codes back then (vs. ZCTA), but it is before the census published tigerline shapefiles. So without the geographic shape, I am not sure how you can solve the problem. I did some googling the census archive. I think this is where the census data for this is:

Census of Population and Housing, 1970, Fifth Count File 5B National
Archives Identifier: 594232 Data Files: 10 (one per ZIP Code Area, based on first digit of ZIP code) Geographic Areas: 12,500 ZIP code areas for Standard Metropolitan Statistical Areas (SMSAs) Technical Documentation: 44 pages and 82 supplemental pages

I would google to see what "commercial" providers who have converted data from archives into shapefiles.

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  • Thanks for the census suggestion. I haven't yet located a copy of that 1970 5th count (that is available to the public). But it did help me take another look at the 1980 census where I've found (and now processed) the MARF5 file.
    – Rob Hoare
    Apr 5, 2014 at 20:34
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The SAS Institute posts quarterly ZIP code files to its website (you need to create a SAS profile to view the files) and they have archived files going back a number of years. That could be helpful! http://support.sas.com/rnd/datavisualization/mapsonline/html/misc.html

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