But Ancestry.com is also actively buying. "We spend over $20 million a year acquiring new content," Scott Sorensen says. On the day of our visit to a clean laboratory, employees are using digital cameras and proprietary software to create high-resolution scans of high school yearbooks. "Yearbooks are incredibly important for genealogy," Thomas MacEntee says, "because they are a great source of finding maiden names for women," a tricky problem when married women often take their husband’s surname. Ancestry.com has acquired a huge number of similar "secondary" sources such as city directories, phone books, and church directories. Once the images are scanned, names are transcribed, metadata is embedded, and the images are uploaded with indexes to Ancestry.com’s website. The company has also bought several other genealogy and archive businesses — smaller competitors — in order to bolster its resources. In April of 2012 it paid $100 million for Archives.com, and that October acquired the photo digitization service 1000memories.

FamilySearch has a website with very similar capabilities, where everything is free. The search isn’t quite as powerful as Ancestry.com’s, and their family-tree making software is not as robust, but the massive collection is growing literally by the day. This growth is fueled by over 150,000 volunteer transcriptionists using a proprietary Java application the company developed itself. Anyone at home can download the app, and in a few minutes transcribe a series of birth, death, or marriage records. This process, called "Indexing," is one of FamilySearch’s most prized and valuable tools. Each year, using its sophisticated transcribing and indexing system, FamilySearch adds 400 million indexed, organized images to its website. The company — which used to distribute its records via microfilm and CD-ROMs — can now move incredibly fast to make its data available to genealogists. The process, from capturing images in the field to making the records available to customers, used to take about 18 months. Now it’s usually less than two, and of course — it’s online, not on rolls of microfilm.

Family history is big business

Ancestry.com and FamilySearch may be the biggest names in online genealogy, but they’re not the only ones by far, and the newer players are moving fast to try to eat up a piece of the growing market. MyHeritage is an Israeli company founded in 2003 whose service operates more like a social network for family members — both the living and the dead — than traditional family tree approaches. The site recently raised $25 million in funding, and is available in 38 languages. Because its early focus was on places such as eastern Europe — where Ancestry.com’s holdings are somewhat weaker — MyHeritage arguably offers something quite unique to American audiences, where it is now making an aggressive push into the market. UK-based FindMyPast.com is also making headway in the American market because exclusive relationships with the governments of England, Scotland, and Wales have essentially given it a monopoly on vital records in those countries. FindMyPast.com’s CEO Chris van der Kuyl is also the president of 4J Studios, the company responsible for bringing Oblivion to the PlayStation 3 and Minecraft to the Xbox. He describes himself as a "technology geek" and thinks about genealogy from that perspective. He got into the family history business by accident when a friend asked him to apply some of his user-experience building skills to a genealogy company’s software. Five years later, he’s still here, working at the helm of the UK’s most powerful family history source. "Technology is empowering," he says, "and the more people [who] have access to the right technology and bring their own data and their own experiences, the more exponentially things get better for everyone. Our mission is to create the most amazing family history experience, to give as many people access to their own story as possible."

By 2010, Ancestry.com had forged a relationship with NBC to bring the UK television series Who Do You Think You Are? to mainstream US audiences. The show featured professional genealogists paired with celebrities like Sarah Jessica Parker, Steve Buscemi, and Spike Lee, sending them on journeys to find the stories of their ancestors. In October of 2012, Ancestry.com — then a publicly traded company — was acquired by a group of investors including CEO Tim Sullivan and European private equity firm Permira Advisers LLP for $1.6 billion dollars. Family history is big business, sure, but searching documents online isn’t the only way to figure out who you are. If you want to get serious and look to the future, well then you’re going to have to spit.

Spitting image: DNA can solve this for you

In Mountain View, California, just around the corner from Google, rest the unassuming headquarters of 23andMe. The company was founded in April of 2006 by a small group including biologist Anne Wojcicki, who is now married to Google cofounder Sergey Brin. 23andMe was created as a personal genome company, its main goal being to put the "power of a person’s health into their own hands," says Catherine Afarian, the company’s public relations manager. While that sounds like a simple mission, it was unheard of just a few years earlier.

Katie recently took the 23andMe DNA test, as well an AncestryDNA test. She did so, she says, because she was curious to see how well science matched up with what she had found in her research. She simply signed up for an account on the website, ordered the DNA test, spit into a tube once the test had been shipped to her, and then registered its barcode number on the website. About eight weeks later, personalized ancestry and health results showed up in her inbox.

At launch, the test cost $999. It was fairly cheap, all things considered, but not something that everyone could afford. This past December, after announcing it had amassed a database of 180,000 DNA tests, 23andMe permanently lowered the cost of the test to $99 in the wake of a large round of financing, and set its sights on getting 1 million tests in its database this year. Though just two percent of Americans have taken such a test, a study conducted by 23andMe indicates that nearly 71 percent of those who haven’t taken one are interested in doing so.

How DNA is inherited

Both Ancestry.com and 23andMe’s genealogical DNA results have similar features. Once your results have been processed — both companies send their tests out to a lab for extraction, then do in-house analysis — you can log into your account and see an approximate composition of your ancestral DNA, which dates back around 500 years. For example, if your grandparents were half Polish and half Irish, your DNA results wouldn’t necessarily reflect that closely, but they would show you roughly where your family came from 10 generations ago. The results for both tests are displayed in a map format (as seen in the diagrams above). "It’s a little bit confusing," Katie says, "because the Ancestry.com test shows that I have about 17 percent Scandinavian DNA, and I haven’t found any Scandinavians in my own research." This opens new, often previously unconsidered, territory for a genealogist to pursue.

Though 23andMe delivered some ancestry results at launch, its "Ancestry Composition" feature — which delivers fairly specific, sophisticated information based on 22 worldwide populations — was launched in August of 2012, just three months after Ancestry.com launched its new DNA testing feature. Both 23andMe and Ancestry.com now offer the same type of test: an autosomal DNA test which delivers specific ancestry information for anyone. Earlier tests for females tested only MtDNA, and delivered only ancestry results from their mothers: a much less specific and useful type of test. The release of a more powerful test by both companies, and the subsequent decrease in cost, means that many people are now signing up. Ancestry.com announced in March that its database comprises of more than 120,000 DNA tests.

But how is the analysis done? Unsurprisingly, it’s complicated and, according to 23andMe’s senior director of research, "not very interesting." Basically, your DNA is tested using several hundred "markers," and compared using the "signal" those markers share strongly in common with geographic populations worldwide. Some markers have a very strong association with a specific location, making the results much more reliable, while others — such as those associated within central Europe, France, and Germany — are much less so, making that fine of a distinction often difficult to assume with a high level of accuracy. The process is further complicated by the fact that most people living today have multiple ancestries, as populations have inevitably migrated and mingled over the course of centuries.

So, if you take the spit test, your DNA is then compared to a set of "reference" tests — the DNA of thousands of people whose origins are well-documented and mapped to geographic locations. In the simplest of terms, where your DNA matches with those reference sets of data, a percentage of your ancestry can be extrapolated to be from that region, too.

A secondary, and possibly more powerful feature of both 23andMe and Ancestry.com’s DNA sites provide something else entirely through similar methods of comparison: they show you other members who have taken the same test who are likely related to you. Both sites give a percentage of confidence in the match, so an example match might say, "We are 95 percent confident that member X is between a fourth to sixth cousin." Now, a sixth cousin is pretty far back in your family tree, but a second or third cousin (and many people who take the test, Ancestry.com tells me, have one or two matches at that level of closeness), is not. A second cousin is the child of your first cousin (your parent’s sibling’s child); a third cousin would mean that you and the other person share great-grandparents. On average, 23andMe says that each person who takes their test has more than 1,000 genetic matches found in the database. You have the option of contacting them — first anonymously — to compare information. Obviously, the more people who take the test, the more matches will be found, and the accuracy of those matches will increase too; hence the big push from both Ancestry.com and 23andMe to get many, many people to take their tests. It also helps explain the recent deep discount — in both cases permanent — to $99.

We’re approaching a future where the mysteries of our ancestral past will simply no longer exist

"We can create a whole new market of people who can make family history discoveries without having to do original research in old historical documents," Tim Sullivan says, calling the recent developments a "revolution in personal genomics." Ancestry.com links your DNA test directly into your tree, and 23andMe offers a less robust feature where you can upload a GEDCOM file to the site, also linking your data to a tree. Personal DNA tests for genealogy aren’t yet widespread, and they haven’t yet realized their full potential. But that’s not very far in the future.

So what does that mean for people who just love digging through documents, whether online or off, searching for tiny clues to link them to the past? In the shortest of short terms, the search continues. But realistically, in the next five to 10 years, it will become increasingly simple to find out who your ancestors were even several generations back, with relatively little effort: genealogy questions are a problem that technology is going to solve, and the foundation has already been laid. And a bit further in the future, it’s entirely realistic to believe that those questions of bloodline, like "Who was my great-grandmother?" simply won’t exist. The role that social networks like Facebook play in laying the groundwork for the future documentation of relationships is an important one — we’re all making more data than ever before. It’s not hard to imagine a future where the mysteries most of us have in our ancestral past will simply no longer exist.

The "stories," they say: that’s what all this data leads us to. A link to our past, not just in birth certificates, dates, and names on a chart, but through stories about who we are via who came before us. In the past decade, genealogy as a hobby has grown exponentially because of the vast amount of searchable data accumulated online: by companies like Ancestry.com, by the government, and by individuals. That trend will only accelerate in the coming years, making the research far more accessible for people with limited time or resources. "For me," Katie says, "I quickly moved past any sense of ‘these are my relatives’ and just fell in love with discovering these completely regular lives from the past, and learning history. I can't ever imaging thinking, "Well, I've found out everything I wanted to know; that's a wrap." Unfortunately for those who love the hunt, the future is about to get way less mysterious.

Video by Billy Disney, Stephen Greenwood, Ryan Manning, and Sam Thonis

Design by Scott Kellum

Infographics by James Chae and Scott Kellum

Photo credits: National Archives and Records Administration, and Katie Notopoulos