Census Guides Home
How to read them and what you can learn from them
Delaware Census records begin in 1800 and can be found for each
successive decade following (e.g. 1810, 1820...). There is no census
for DE for the years 1790 or 1890. They did not survive. There was a
Delaware census/tax assessment list for 1782 which lists a limited
number of individuals in Delaware, but can still be quite useful.
The Census records from 1800-1840 list only the head of household (HOH)
and each person in that household is marked by their age. In order to
successfully read a census record, you will need to know what ages each
column covers. Below are the 1800 census record for John Ferriss of
Pencader Hundred, New Castle County, DE (p. 236) and the 1810 census
record for a John Feris of Mill Creek Hundred, New Castle County, DE
Notice "Ferriss" was written as "Ferrifs". When two "S's" were in a
name, the first "s" was written like an "f".
[Note: the image is slightly crooked. The numbers at the bottom of the
page are the totals for each column]
I have labeled each column in the census with a number (1-12). Each
number indicates how many of a certain age are in John's household.
Note: only the 1800 & 1810 Censuses have 12 columns. 1820 has an
extra column for 16-17 year old males (13 columns) and the 1830-1840
Census have even more.
Below is an 1820 Census for
John Ferriss of Mill Creek Hundred, New Castle County, DE (p.133).
1800 & 1810 Censuses
Key for 1820 Census
Columns 1 - 5 are males
Columns 1-6 are males
Columns 6-10 are females
Columns 7-11 are females
Columns 11 & 12 are servants/slaves
Columns 12-13 are servants/slaves
males 0-9 years of age
males 0-9 years of age
2 = males 10-15 years of age
2 = males 10-15 years of age
3 = males 16-25 years of age
3 = males 16-17 years of age
4 = males 26-44 years of age
4 = males 18-25 years of age
5 = males 45+ years of age
5 = males 26-44 years of age
6 = females 0-9
6 = males 45+
7 = females 10-15
8 = females 16-25
9 = females 26-44
10 = females 45+
11 = females 45+
we learn from these?
If we look again at John's 1800 census (above), we can conclude that
there were 3 males 10-15, 3 males 16-25, 1 male 45+, 4 females 16-25
and 1 female 45+.
Now, it's not always the case that the oldest person in a household was
the head of household, but it is more often the case than not.
It looks like John was the 45+ male, his wife was probably the 45+
female and they had 10 likely children in their household, all under 25
yrs of age. The census record is not proof of this however.
There is no proof that the 45+ female is married to the 45+ male.
There is no proof that any of the children are John's children...or
children of the supposed wife.
The enumerator (the person that goes to each home and takes down the
information) is not always to be trusted with the information he
recorded. People do make mistakes.
The enumerator asks someone at the house (and not always the head of
household) about what information he was recording. Does the husband
always know his wife's age, did any of them lie? Who knows.
I like to use the census records as a guide to aide me in where to
search next. I'm not saying that all census records are unreliable, but
I just tend to take the information I find there with a grain of salt.
If someone's age on the census is 10-15 in 1820, I won't rule out a
person who is listed as 27 years old in 1850 as being the same person.
As you look at census records more and more, you may find certain
people got significantly younger with each successive census. In my
research, this tends to occur more often with women than with men.
This this the same guy?
If you look at all three censuses, you may notice that they belong to
different people, and not just because they are from two different
hundreds in New Castle County or because of the spelling of the
surname. Even though it's possible John Ferriss could've moved from
Pencader to Mill Creek, the ages don't add up at all. The Pencader John
Ferriss of 1800 is much younger than the 1810 John Ferriss of Mill
Creek. If John was 45+ in 1800, it is likely not the same John who was
26-44 in 1810.
The Mill Creek John from 1810-1820 could very well have been the same
person. Let's look at it in another way.
2 males 0-9
3 males 10-15 [Two of the 0-9 yr olds
from 1810 who couldn't have been older than 5 in 1810, and one 10 yr
old possibly born after the census of 1810]
1 male 16-25
1 male 45+ [The 26-44 yr old from
1810, meaning he was at least 35 in 1810 and born by 1775]
1 male 26-44
1 female 16-25 [The 0-9 yr old from 1810, meaning she was
at least 6 yrs old in 1810 and born by 1804]
1 female 0-9
1 female 45+ [One of the 26-44 yr
old females from 1810, the other one likely left the household or died]
2 females 26-44
The 16-25 year old male from 1810 likely left the household and may
have married between 1810 and 1820. A good time period to look for a
marriage record. It's also a good time to look for a deed since he left
the household and may have bought land to share with his new wife.
When you look at one census record, you have a wide range of birthdates
for each individual. When you look at two or more, you can narrow it
Let's look at the 2 males 0-9 (1810) and the 3 males 10-15 (1820).
Looking at the 1810 census alone, you would conclude the 2 males were
born between 1801 and 1810. That's a total of 9 years when they
could've been born. If you look at the 1820 census you'll see that
since there was no column marked for a 16-17 yr old or an 18-25 yr old,
the oldest they could've been was 15. If we subtract 10 years from 15,
the oldest they could've been in 1810 was 5. Now we have a range of 0-5
in 1810 rather than 0-9. We've knocked off 4 years. Now these 2 males
were born between 1805-1810. The 3rd male in 1820 was likely born in
1810, but after the census was taken.
Let's say you only saw the 1820 census. You see the oldest make is 45+
years old. If you then see the 1810 census, you'll see he was 26-44 in
1810. Now, subtract 10 years from 45+ and you'll get 35+. You know he
had to have been between 35 and 44 years old in 1810.
The 26-44 age range is the most annoying for me. It covers almost 20
years unlike the other columns. With this age range, a person can fit
into the same column for two consecutive census years.
When you add the information gathered from census records to the
information you get from deeds, wills & probates or tax assessment
records, you can learn more, especially when there was more than one
person with the same first name and surname.