Two kinds of census citation
“Census” can mean two different things, and the citation depends on which you are using:
- Historical census records, such as a 1940 population schedule page showing your ancestor’s household, usually viewed as a digital image on a records website.
- Modern Census Bureau data, such as a table or dataset on data.census.gov used for statistics.
Genealogists mostly need the first. Chicago Manual of Style (Notes and Bibliography) is the base for the widely used genealogy citation reference Evidence Explained by Elizabeth Shown Mills, which adapts Chicago-style notes to records like these. The templates below follow that general approach. If a teacher, journal or publisher gives you a specific style sheet, follow it.
What to include in a historical census citation
A census citation should let a reader find the same page. Include:
- The census year and the phrase “U.S. census”
- County and state
- The type of schedule (for example, population schedule)
- The town, township or ward, and the enumeration district where shown
- Page or sheet number and, where available, the household or dwelling and family number
- The name of the person or head of household you are citing
- Where you viewed it: the website or database, URL, and your access date
- Where the original publication is described, such as the National Archives microfilm publication number
Footnote template and example
Template:
1. [Year] U.S. census, [county], [state], population schedule, [place], enumeration district [number], sheet [number], household [number], [name]; digital image, [website] ([URL] : accessed [date]); citing [National Archives microfilm publication].
The example below uses invented details to show the format only:
1. 1940 U.S. census, Cook County, Illinois, population schedule, Chicago, enumeration district 103-1, sheet 4A, household 72, Maria Rossi; digital image, Ancestry.com (https://www.ancestry.com : accessed 14 October 2026); citing National Archives microfilm publication T627.
T627 is the National Archives microfilm series for the 1940 census. Other census years use different publication numbers, so check the source information the website provides for the year you are citing.
Bibliography entry
Many genealogists list census sources in a bibliography or source list by record group rather than by every person. A simplified entry might read:
U.S. Census Bureau. 1940 U.S. Census, Cook County, Illinois. Population schedules. Digital images. Ancestry.com. https://www.ancestry.com.
Check whether your publisher wants individual entries or grouped entries.
Subsequent notes
After the first full footnote, later citations to the same page can be shortened, for example:
2. 1940 U.S. census, Cook County, Illinois, Chicago, ED 103-1, sheet 4A, household 72, Maria Rossi.
If you cite a different person on the same page, the shortened form changes only the name.
Citing modern Census Bureau data tables
For statistical data, the Census Bureau provides citation guidance and a “Cite” tool on data.census.gov. The core elements it points to are the author (U.S. Census Bureau), the table title and number, the product name, the vintage or release year, the URL and an access date. Look at the tool’s current output and match it to the style your publisher requires.
Common mistakes
- Leaving out the access date. Online records can change, so include when you viewed them.
- Citing only the index. An index entry is a finding aid. Cite the image of the original page when you have seen it, and say so if you used only an index.
- Missing page and household details. Without sheet and household numbers, the reader cannot find your ancestor.
- Mixing styles. Choose one pattern and apply it to every note.
- Forgetting that the 1890 census is largely missing. Most of the 1890 population schedules were lost in a fire in 1921, so you will usually be citing other years. For a state-level example of what survives, see Virginia census records.
Frequently asked questions
How do I cite a Chicago citation?
Chicago Notes and Bibliography uses a numbered footnote or endnote for each source plus a bibliography at the end. The first note gives full details; later notes can be shortened.
How do I cite the US census?
For a historical record, use the footnote format above. For statistical tables, use the Census Bureau’s own citation guidance and the Cite tool on data.census.gov.
How do you format figure captions in Chicago style?
Chicago generally places a figure number and a short description below the image, with a credit line giving the source. If you reproduce a census page, include the citation or a shortened note in the credit.
Does history use MLA or Chicago?
History is the field most associated with Chicago style, which is why it is a common choice for historical and genealogical writing. Individual instructors and journals may differ, so confirm which one applies to you.
Related guides
Citations work best when you record them as you research. See how to organize genealogy research for building that habit, and our genealogy research report template for where citations fit in a written report.