How does genealogy work?

How does genealogy work?
(Image credit: Getty Images)

Simply put, genealogy is tracing back your family lines. You start with yourself, then map out the details of your parents, grandparents, and further ancestors. The best genealogy sites can help you do this – but you can also go it alone, if you’re comfortable navigating databases and old records. 

These records tend to be scattered across public resources, which is why most people use a dedicated service. To help you get started though, we’ve pulled together a guide, which should help you figure out how genealogy works.

What is genealogy and how do genealogy sites work? 

Not to be confused with DNA testing, genealogy is mapping out your family lines. This can be done through a manner of resources, either by confirming details with living relatives or scouring public record databases. 

In the last decade or so, a lot of websites have sprung up that provide comprehensive services for this. These companies have done most of the hard work for you, by scanning and uploading old physical documents, then turning them into digital databases that are super easy to search.

In addition to making it easier to search these databases, these websites also encourage people to deposit their own information on the site. As such, when you trawl through these online catalogues, you could also stumble across a relative who’s halfway round the globe and has entered their own details. 

Whether you decide to go via a dedicated service or do your own research, it’s always a messy process, as there’s no one specific resource where you can find all of your family connections – you’ll have to go through multiple records to find what you need. For this reason alone, a lot of people rely on using things like the best family tree makers to keep track of all the data. 

Records and databases: Where to start with genealogy 

Any public database can be a rich resource for family research, but there are a few key places where you should start. We’ve outlined the main ones below – these will all likely be stored on the best genealogy websites too, but you can also access most of these documents directly yourself. 

As a side note, genealogy websites tend to flag when they have information that matches your search, but if you’re accessing these databases directly you’ll have to do your own detective work. The benefit of this is you could discover a connection that a computer wouldn’t have made, but it might take longer to trace those connections, too. 

Census records

Looked after by the National Archives and Records Administration (NARA), the census database becomes publicly available after 75 years. This means you can currently look through the 1940 census, which has been uploaded online here, and in 2022 you’ll be able to look through the 1950 census as well.

There’s a wealth of information included in this public database, which is why it’s a useful starting point (as long as you can trace your lineage back that far.) Scrolling through the notes, you’ll be able to find details on a person’s location, name, relatives, personal appearance, education, employment and income. The only drawback is that there are reams of information, so you’ll need to know some details about your subject before you start searching.

How does genealogy work?

(Image credit: Getty Images)

Immigration records 

Ship passenger arrival records and border crossing documents are another useful resource. There are various places where this information is publicly available but the most comprehensive database is again looked after by the National Archives. Unfortunately, these documents haven’t all been digitized yet, so if you want to get your hands on the originals you may need to visit your local NARA facility or take a trip to the National Archives building in Washington, DC.

That’s not to say that there aren’t any of these documents available online. You can explore extensive passenger lists via the Statue of Liberty Ellis Island website, and other paid-for services like have pockets of information on immigration history too. Familysearch, which is completely free, has also compiled a list of where you might find some information on this subject in each state.  

Birth records 

Birth records aren’t public information in the US, but you can usually request a copy of a person's record if you’re an immediate family member (child, parent, spouse or sibling) or if it’s your own. You’ll have to get in touch with either your local health department or vital records office to see if they can send you this information, and bear in mind that there is usually a fee. This is a good starting point if you have very limited family information available to you.

A lot of states allow birth certificates to become public records after 125 years, so if you’re trying to track down older family lineage this could still come in handy.

Death records and obituaries 

Unlike births, deaths are usually public records, but you’ll have to know some of the details for a copy to be disclosed to you, such as full name, place and date of death. You’ll also usually have to prove why you need to obtain a copy. Again, these are looked after by the state’s health department or vital records office.

You might have more luck searching for obituaries, but again there isn’t a free consolidated database for this. If you know the state where the subject died, you could try researching in the archives of the main local newspaper. But this is really where the dedicated genealogy sites come into their own and you might find it easier to get a short subscription (or even try a quick free trial) on something like

Marriage records 

These are probably the most straightforward records to access via either your state’s health department or vital records office, as these documents are entirely public. You’ll still usually have to pay the department a fee and provide some details on what you’re looking for, but in theory these types of records are open to anyone who’s conducting some research. These documents can be illuminating, as they can reveal pre-marital names and new family ties. 

More ways to people search 

If you’re trying to conduct searches for other, non-genealogy reasons – maybe to connect with old friends, or maybe you’re trying to find a past criminal record – we recommend that you try out one of the best people search sites or the best background checker. These are much more efficient for those kinds of searches.

Just bear in mind that there are legalities surrounding how you can use this information. You can’t base decisions on work and employment, lending credit, confirming a tenancy or extending a scholarship using these check services. 

Ruth Gaukrodger

Ruth has worked across both print and online media for more than five years, contributing to national newspaper titles and popular tech sites. She has held a number of journalist roles alongside more senior editorial positions, and is now the Digital Learning and Hobbies editor for the Top Ten Reviews brand.