1940 Census | Page 7 | Newberry

1940 Census

All of the hoopla over the release of the 1940 U.S. federal census is long over. The census is indexed and available online. And we’ve all added it to our list of “must check” resources. But have we taken the time to fully understand how to interpret all the information that is included on the census? Are we missing any important clues? Do you know What does an entry of “M2” means in the marriage column of the 1910 census and what “M7” means in 1940?

Constance Potter’s article, “The 1940 Census Re-visited” was published in the winter 2012 issue of the NARA publication, Prologue. It contains great tips on how to interpret the information on the census. Ms. Potter also shows how details in the census can lead to other federal records.

Increase your census IQ by reviewing the instructions given to the enumerators. The abridged instructions for the 1940 census are on the NARA website. This suggestion holds for other census years as well. Measuring America: The Decennial Censuses from 1790-2000 is another great online resource for understanding each of the U.S census population schedules. This volume was published in 2002 by the Census Bureau and includes all census questions, enumerators instructions, and brief histories of every census from 1790-2000.

Oh, and in case you were wondering, “M2” in 1910 indicates that the person was married more than once, but doesn’t indicate the number of marriages (there are no “M3” or “M4” entries). In 1940, “M7” meant married but not living with a spouse.


First I must say, what a fantastic resource! The dedication, and generosity throughout your site is refreshing and much appreciated. My question refers to locating census records from the Illinois institutions. Would I need to first know the ED where an institution was located? What if I am unsure which institution housed the person? I guess maybe Im looking for a separate searchable source for inmates/prisoners, state and federal who were in Illinois facilities. Any ideas? Thank you in advance.
@ Tani - Thank you for the kind words! The census records for institutions are included in the population schedules for the various census years, based on ED. You can search any of the census databases by name for inmates/prisoners, just as you would for any other individual. If you want to search an institution page-by-page, I suggest you find the ED using the Unified Census ED Finder at: http://stevemorse.org/census/unified.html. Also, be sure to check the enumerator's guide to see if there were special instructions when recording those living and working at an institutions. You can find the instructions at: https://usa.ipums.org/usa/voliii/tEnumInstr.shtml

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