Age brackets. Age brackets were divided into five categories and there were columns for all other free persons and slaves to be counted.
Do not assume. Do not assume that 45+ female is married to the 45+ male, the children on home belong to the family, or the children belong to the either the mother or head of household.
Slaves. Slaves where to be counted as 3/5th of person. We are not sure that the number in the slaves category is actual slaves or the addition of 3/5th for each slave.
Free white males and females. Because we are given more age groups for Free White Males and Free White Females, it makes easier for us to identify the exact person when we are presented names through other documents or later censuses. We are also able to make a little more sense of 1790 census with the numbers that are presented in the limited age categories.
Category tabulation. Numbers shown in the categories include all persons who were in the home such as family, relatives, friends, employees, visitors, and boarders.
Search other records. When you combine the age category with other records such as probate inventories and tax lists, you may be able to determine the names of the family and their birth order.
Ballpark. The age range provided in the categories only gives us a “ballpark” number. The ball park figure is helpful in tracking the head of household from one census to the next especially if the name remains the same. We can also use the figure to help build an estimation of the family composition that needs to be confirmed with other records (e.g., church, wills/probate, land).
Oldest person. The oldest person listed in the age groups may not have been the head of household. The individual could have been a parent or grandparent.
Family scenarios. You can use the age category to develop family scenarios about individuals who have died. For example, as you move forward in the census, you may find the age of a spouse to be much older or younger such as in the case where a wife is too young for some of the children being listed. You may find young children listed in one census and gone in the next census which could mean that the child is dead or living somewhere else during the census. A death of male can give clues to search for a will/probate record. If a female in an age bracket is missing, she could have died or married.
Age gaps. When you find age gaps in children it could hint for a number of issues such as the child could have died (Note: Search to see if death, church or cemetery records exist), there could be a second marriage or merged family families (Note: search for marriage records where the family lived at the time.)
Estimated birth years. As you move forward and backward in the 1790-1840 censuses create a chart for the known and/or suspect families. Include the head of household, ages ranges by male and female with their estimated birth years. See the article, “Using the census to calculate the birth year of your ancestor.” When you find the same or similar age ranges by male and female for all or partial members of the family, you have a much better chance of being focused on the right group.