Making Sense of Pre-1850 Census Records

As many of you may have heard, we are currently working to enhance the images of all U.S. Federal Censuses and indexes for seven. (Click here to learn more.) This past week the improved 1820, 1830, and 1840 U.S. Federal Censuses were the latest update to be re-indexed and new search fields are available for these years.

At first glance, pre-1850 censuses may not seem to be of much value. Only the name of the head-of-household is listed, followed by unruly columns full of tick-marks and tallies. But behind those tick-marks and tallies your ancestors are waiting to be discovered. Here are some tips to help you learn more about them.

Got Charts?
Before delving into pre-1850 records, create a chart for the family you’re seeking. Estimate birth years wherever you can and project the approximate age for each census year. (See the sample below.
) Then create a template of what the family might look like in the census using the blank census forms available from .
Don’t discount families with extra people in the household. These could be children who died young, or extended family living in the household (e.g., in-laws, the spouse of an older child, etc.).


Create pre-1850 “Cheat Sheets.”
It can also be helpful to use those same blank forms to create a kind of “cheat sheet” for each census column heading. In the first few blank lines write in the years associated with that heading. For example, in the 1830 census, those under the heading “under five years of age” would have been born roughly between 1826 and 1830; those “of five and under 10” would have been born between 1821 and 1825, etc. Now when you record your ancestor’s census record below that, it will be easy to see the birth date frames for each column.

These dates may be off by a year or so depending on when a person was born in relation to when the actual census taker arrived. Bear in mind that these early censuses were taken by enumerators visiting every household and transportation over the young and largely rural country was of the four-legged variety. Some of the censuses took a year or more to complete, and although the “official instructions” may have been to record ages as of the official census date, that wasn’t always the case. You can learn more about the official census dates at

Look at the Big Picture
By using several pre-1850 censuses together, you may be able to narrow the window for some birth ages. For example, you’ve found John Q. Ancestor in the 1840 census and it says he was between 40 and 50 years old (born roughly between 1790 and 1799). The 1830 census is consistent and lists him between 30 and 40 years old.

However, in 1820 the age groupings are a bit different. This time someone born between 1790 and 1799 could have fallen into one of two categories—of 16 and under 26 (born between 1795 and 1804) or of 26 and under 45 (born between 1775 and 1794). This narrows the age span to five years, rather than ten.

Another Interesting Tidbit on 1820
If you have a free white male ancestor born between 1802 and 1804, you’ll be able to narrow that age down to those three years. There are columns for males “between 16 and 18” (born between 1802 and 1804) and again for males “of 16 and under 26” (born between 1795 and 1804). It’s also important to be aware that he’ll be counted twice, once under each category, so be careful not to add an extra teenager. Also, you can estimate that any males counted in the 16-25 range who are not in the 16-18 field, will have been born roughly between 1795 and 1801.

Those Other Columns. . .
Although the information isn’t what you’ll find in 1850 censuses and later, there is some additional information to be gleaned. Beginning in 1820 we begin to see some occupational clues with the addition of columns for the “number of persons engaged in” agriculture, commerce, or manufactures. The 1830 enumeration omits this occupational information, but in 1840 we see the addition of mining; navigation of the ocean; navigation of canals, lakes, rivers; and “learned professional engineers” as well.

The 1830 and 1840 censuses begin collecting statistics on the number of deaf, dumb, blind, and 1840 adds the number of “insane” members of the household.

Unique to 1840 is a field for the names of “Pensioners for Revolutionary or military services” along with their age. It also asks about educational status and how many adults were illiterate.

Giving the Statistics a Name
While research in pre-1850 census records can be challenging, there is still much to appreciate. We can assign temporary names to them like Male A, Female B, and the added date ranges can help us to begin to see the family take shape.

While a search may begin with cold and lifeless statistics, with the help of court, church, newspapers and other available sources (most of which are easier to locate once the census tells where they lived), a clearer image will begin to emerge. Through the combined use of the census and other records those tallies become our living and breathing ancestors.