UPDATED MARCH 2020:
NEW! Let this FREE tool do the work for you as you search on Ancestry.com
U.S. county boundaries have changed over 17,600 times since America was settled in colonial times. Don’t sabotage your search for ancestors by not knowing the correct county for the historical years you are researching.
While searching on Ancestry, the free Historical U.S. Counties Auto-Checker extension for Google Chrome automatically checks that the county existed in the year you are searching, warns of boundary changes, and links to historical county lines on Google Maps for the place and years you are searching!
Install for free today and never let an ancestor fall of the map again!
OK, let’s say you’re searching in the 1880 United States Federal Census for an ancestor that you know lived in Denver, Colorado at that time. The ancestor’s name is James Smith and you think he was born sometime around 1850.
search form, as shown at right. As you start typing “Denver” into the “Lived in” box, Ancestry very kindly offers you suggestions.
You think to yourself, “Why thank you, I’ll choose the first option, ‘Denver, Denver, Colorado, USA’. Sounds about right.”
You click Search and get the results shown below:
7,611 search results! Ouch. And that’s with the “Exact” boxes checked next to the First and Last Names as shown above.
So you think, “Hmm, time to edit my search and check some more ‘Exact’ boxes so I can narrow down my search results.” Since you know your ancestor lived in Denver, you check the “Exact to this place” box, as shown at right. Assuming this should give you what you’re looking for, you click Search.
This masterpiece result is what you get in return:
“Wait, how in the world could there be ZERO results?!”, you fume. “And for a common name like James Smith??”
As you’re scratching your head and thinking about engaging Ancestry in a Twitter-storm, you remember something about changing county boundaries that some blogger named Randy Majors seems to drone on about. You think, “Could that be relevant in this case? I doubt it because I live in Denver and I know that Denver is in Denver County.”
But something tells you to check anyway. You go to the free Historical U.S. County Boundary Maps tool found at randymajors.org/p/maps. Pretty easy, just start typing “Denver, CO” into the top box below, and “1880” for the “As of date” and click “Go!” This is what you see:
“Eureka!”, you exclaim. Or actually “Arapahoe!”, since that’s the county Denver was a part of in 1880, according to the highlighted box at the top of the map. (Learn more about where this information comes from below the map here.)
Armed with this invaluable sliver of wisdom, you return to the trusty Ancestry 1880 Census search form and edit your search.
This time, you start typing “Denver, Arap…” into the “Lived In” box (and you may or may not get an auto-complete suggestion). Either way, you stubbornly type the whole thing: “Denver, Arapahoe County, Colorado, USA” and then check the “Exact to this place” box again, as shown here:
You click Search and hold your breath.
But not for too long, as Ancestry quickly returns a truly beautifully manageable quantity of 10 search results:
Happily finding the James Smith you were looking for, you begin your next search: Robert Johnson, who lived in what is now Chicago in around 1830. That’s Cook County, right? Ah, but now you can’t be fooled!
And lest you think this is a limitation of Ancestry’s search, try the same thing at FamilySearch and you will get the same ZERO results for a James Smith born around 1850 if you type “Denver, Denver, Colorado” into the Residence Place box, and you will get around 10 results if you type “Denver, Arapahoe, Colorado”.
Technical side-note: My advice about typing the full place name (with the correct county) in the form “Denver, Arapahoe, Colorado, USA” applies across ALL Search forms, whether you do a global search across the entire Ancestry website or a search within a specific Collection. So even searching within the 1880 US Federal Census, “Denver, Denver, Colorado, USA” will automatically appear as you start typing “Denver” — even though Arapahoe County was the only county in which Denver, Colorado existed in 1880.
So in conclusion, is it necessary to know the correct county name for the place and date you are searching? Asked and answered (hopefully!) :)
Should you check the historical County information every single time you search? You probably should if it’s the first time you’re searching in that area in a given year. But at a minimum, my suggestion is this:
If you check an “Exact” location box when searching and get either ZERO or other very erratic results, it could very well be that you’re looking in the wrong county. And now you know how to quickly find the right county! Enjoy!
(And be sure to read the “Quick Tips for Using this Tool” just below the map)