Learn How to Use U.S. Census Records

September 4, 2018  - by 

U.S. census records can offer you a window into your ancestors’ stories—and clues about new relatives to add to your family tree. Here’s how to use U.S. census records to reconstruct your family history.

When searching for information about ancestors who lived in the United States, federal census records should be one of the very first sources you consult. Census records can help you reconstruct entire family groups and identify previously unknown relatives. Sometimes you can even discover interesting details and stories that help you better understand their lives.

Every major English-language genealogy website should have U.S. census records from 1790 to 1940, and the entire collections for these censuses are free to search on FamilySearch. So there’s no reason not to explore them!

Here’s more on what you should know about U.S. census records and how to search them:

Differences between U.S. Censuses

Censuses have been taken by the U.S. government every 10 years since 1790. Remarkably, nearly all have survived—except for the 1890 census, which was lost in a fire, and a few lost fragments from other years. The most recent census available to the public is the 1940 census.

Census details vary from year to year, with some of the more recent ones offering the most details. Since 1880, censuses can often help you reconstruct your family tree because they provide genealogy-rich information like names, relationships, approximate birth years, marital status, birthplaces, and parents’ birthplaces. Some details shed light on your ancestors’ immigration and naturalization, homeownership, literacy, education, childbearing history, neighborhood makeup, and more.

Changes in US Census records

1790 U.S. Census Record

Recent US census records

1940 U.S. Census Record

Older censuses aren’t quite so detailed. In 1850, 1860, and 1870, you’ll find each family member listed, but not their relationship to the head of the household. You can often guess at the family structure, though, since the father was supposed to be listed first, then the mother, then their children beginning with the oldest, then other relatives followed by nonrelatives, such as boarders or servants. (You’ll want to consult other records to confirm those inferred family relationships.)

Before 1850, censuses included only skeletal information about each household. The head of household is named, but others are tallied only by category, such as the number of free white males and females, enslaved people, and others. Often, you’ll need to use these census entries in combination with other records to reconstruct your family tree.

Tips and Tricks to Search U.S. Census Records

These tips will help you get the most out of U.S. census records for your genealogy.

1. Search for every relative in every census.

Different census entries for the same person may reveal unique information, so it’s worth finding and studying each one in which that person appeared. Details you learn from each one can help you more confidently recognize your relatives in the next entry you see.

For example, Andrew and Rose O’Hotnicky of Olyphant, Pennsylvania, first appear as a couple in 1910 with their newborn baby, Edward:

How to research genealogy using U.S. Census Records

All census entries shown here are from the population schedules for Pennyslvania, Lackawanna County. Digital images are from FamilySearch.org.

In 1920, 3 children are listed—but no Edward, who had died:

Search U.S. Census Records

In this entry, the parents appear on the bottom of one page, and the children appear on the next page; we’ve cropped and stitched them together for easier viewing. You may need to page forward or backward through the online images to see a family’s full entry.

Ten years later, in the 1930 census, Andrew’s widowed mother Caroline appears in their household:

U.S. Census Records and Genealogy Research

Learning Caroline’s identity makes it easier to jump back in time and identify Andrew in the 1900 census. Here he appears as a child in his mother’s household, along with several siblings and even his maternal grandfather (who, again, appears on the following page, so you have to page forward to see him in the household):

Where to find U.S. Census Records

By default, censuses generally reported the man as head of household (column 4). But here, Caroline’s marital status (reported in column 9) identifies her as a widow, so she is head of household. The last 2 columns shown reveal how many children Caroline had borne (11) and how many were still alive at the time (7). All 7 living children are named in this entry. If you wanted to reconstruct her entire family, you would look for evidence of her deceased spouse and children in earlier records.

2. Look for Variations in Entries

When you’re searching censuses, you may find relatives identified at different times under their first or middle names, by nicknames, or by their initials. Their ages may be reported inconsistently, too. Name spellings in original records especially vary before the 1900s and for immigrant families during the early 1900s. Names may also have been transcribed differently (Andrew’s surname has been indexed as O Hatnicky, Ohotinsky, Ohotoricky, and even Shotnicky.)

Sometimes your genealogy website search engine will recognize these variations and present them to you in your search results, which you can then click on to explore in more detail. Other times, you may need to search several name variations (and even different genealogy websites, where the indexing and search engine may be different) before you locate an ancestor’s entry.

3. Read the Entire Entry and Even Those of the Neighbors

If you read the details in census form columns further to the right than the snippets shown above, you’ll learn several more things about Andrew and Rose, including that their parents were Eastern European immigrants and that Andrew’s career evolved between censuses from coal mining to driving a fire truck. Studying the entries over the years also reveals that the couple lived for decades in the same neighborhood, surrounded by other working-class families of Eastern European descent.

Noticing those who lived nearby sometimes leads you to additional relatives. Rose’s maiden name was Krankota, as revealed by her marriage license application, but her parents weren’t named. However, in 1910, an older Krankota family lived on the same street as Rose and Andrew. The mother in that family reported having 4 living children, but only 3 lived at home. Further research revealed this to be Rose’s family of origin and helps expand the ancestry in her branch of the family tree.

For More on How to Use U.S. Census Records

Where to Explore U.S. Census Records

Try it yourself: Visit FamilySearch or another favorite genealogy website, and search for your relatives in U.S. census records. If you have a tree on the site, search from a relative’s individual profile (so you don’t have to enter all of their personal information), and limit your search results by record type to census records. Otherwise, enter a relative’s name in the main search box, and again limit search results to census records.


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  1. I am still waiting for FamilySearch to give us the ability to add alternate information. That is the reason that the hint feature in Ancestry is light years ahead of FamilySearch.

  2. My understanding is that three copies of the 1850, 1860 and 1870 censuses were recorded. How were these three copies were archived? Which one is at NARA? Were the other copies stored at the state or local level? In looking at a microfilmed version is it possible to determine which copy is being read? With three copies I assume that two were transcripts of the original and might be better, clearer copies.
    Robert Woodley

    1. Marcia, I’m sorry you’re encountering this issue! Thank you for letting us know. I’ve sent your comment to the appropriate parties; hopefully it will be fixed soon!

  3. That is an excellent explanation of why to look for each person in every census. I do that and thought perhaps people might think me overdoing things. Now I know that I’m doing the right thing.