New and simple online tool uses Google Maps to show historical county boundaries


Thanks so much for all of the interest in this tool, and for your positive comments and constructive feedback!  I’ve incorporated several enhancements into the current version.

We all know the importance of county governments for maintaining various types of records that are useful for genealogical research.  But how often have you tried searching for an ancestor’s historical records for a given county, only to realize that you were searching in the right place but the wrong county?  In fact, according to John H. Long, the director of the Atlas of Historical County Boundaries Project at the Newberry Library, “the average number of boundary changes per county in the U.S. is 4.5”.  This means that there’s a very good chance that you are sometimes looking in the wrong county for some of your historical genealogical records.

Using the fantastic information from the Atlas of Historical County Boundaries, I’ve created an online Historical County Boundary Maps tool based on Google Maps.  You can type in ANY PRESENT-DAY PLACE in the U.S. and ANY HISTORICAL YEAR to see the map of county boundaries then in effect, along with all of the current Google Maps places, roads, etc to put the historical map in a current and familiar context!  You can then click any county on the map to see the specific history of the boundary changes, and type in different years to see the boundary changes over time.  Here’s how to do it:

1. Go to this page on my website:  Historical County Boundary Maps

2. Type a PRESENT-day Place and a HISTORICAL Year, then hit the “Go!” button.  The place you type MUST be a PRESENT-day city, town, or county; you can even type a current day address or road name*.  The year can be from the mid-1600s (depending on date of state formation) through the year 2000.

3. Once you see county boundaries, click inside any county to see its name and details.  The info window will list the county name and when that county’s then-current boundaries (as of the date you selected) went into effect.  Type a year prior to the effective date to see the prior boundaries.

Consider subscribing to this blog using one of the options on the right side of the page in order to receive notification of updates and enhancements.


* The Place box uses a standard Google Maps geocoding engine, therefore you can type present-day street addresses, road names, points of interest, and the like, and then type in the correct historical year to see what county that address or road was located in back then (e.g. type “Silver Oaks Cemetery, Tyner, TN” or “Old Lee Highway, Tyner, TN” together with the year 1880).  Of course, this doesn’t account for addresses or road names that may have changed, so if you suspect that, then just start with the right present-day town or city name.

– This tool works best with Chrome, Safari (including iPad), and many other browsers.  There are known issues with some versions of Internet Explorer.  For some mobile browsers, click the “View web version” link at the bottom of this page on the mobile browser.

– Occasionally, county lines may take up to 10 seconds to appear; if the county lines never appear, try refreshing the page (F5) and try your search again.

– This tool uses an experimental Google Maps API feature called Fusion Table Layers.  The underlying county boundary map files used are quite large, and Google Fusion Tables are themselves a beta product.  As with any new and innovative technology, don’t be surprised if things occasionally don’t function as expected.

– Currently, county boundaries must be viewed one state at a time.


– The fantastic source of the historical county boundaries and related information used in this tool is the Atlas of Historical County Boundaries, a project of The Dr. William M. Scholl Center for American History and Culture at The Newberry Library in Chicago, Illinois.  The information is included in my website under the creative commons license shown on the bottom of the linked page.

I hope you find this tool useful in your research!  I plan to continue to enhance the tool and add functionality, so feel free to leave comments below on what you like, and what you’d like to see improved or added to future versions.

33 thoughts on “New and simple online tool uses Google Maps to show historical county boundaries”

  1. Hi Jo,

    The site was operating very slowly a bit earlier today, but seems to be operating normally now. Please let me know if you still encounter issues.

    I hope you are finding the maps and info you need using the tool.

  2. In response to comments from Danno,

    Thank you for your comments. Those county boundaries in the colonial-to-independence era were quite complicated and shifting indeed.

    As you mentioned, Virginia also laid claim to that southwestern part of Pennsylvania until around 1780. So there were overlapping claims.

    Here's the good news: there's a way to view overlapping claims for the same area in the map tool, but its not exactly intuitive. (This same approach works well for any time you're looking at the "frontier" region of a state during the U.S.'s westward migration as well). Here's how to do it for the Waynesburg, PA area:

    First, type in Virginia for the place, and 1774 for the year and click Go.
    Then scroll and zoom the map to find what is Waynesburg, PA today.
    Click near Waynesburg, and it shows the county (along with exact date of formation and source law/statute) as:
    – 1774: W. Augusta District
    – Type 1777 and click Go, and click again near Waynesburg, it states: Monongalia (and, as you state, the western part of what is today Greene County PA shows as Ohio County, VA)

    Next, to see what Pennsylvania was laying claim to at the time, type Waynesburg, PA for place, and let's say 1770 for the year and click Go.
    Click near Waynesburg, and it shows the county (along with exact date of formation and source law/statute) as:
    – 1770: Cumberland
    – Type 1772 and click Go, and click again near Waynesburg, it shows: Bedford
    – Type 1774 and click Go, and click again near Waynesburg, it shows: Westmoreland
    – Type 1777 and click Go, and click again near Waynesburg, it shows: Monongalia
    – Type 1781 and click Go, and click again near Waynesburg, it shows: Westmoreland
    – Type 1782 and click Go, and click again near Waynesburg, it shows: Washington
    – Type 1797 and click Go, and click again near Waynesburg, it shows: Greene

    Whew! That area of the country is an excellent example of looking at one place (say Waynesburg), and it being in no less than 7 different counties over about a 25 year period!

    So, all in all, with the non-intuitive workaround described above, it appears that this matches up quite closely with what you described.

    Thanks much for the feedback, and I hope you get good use from the tool.

  3. I noticed some of the Pennsylvania counties are wrong or at least Greene county in the southwestern corner of the state. Say if you type in Waynesburg the county seat of Greene county, PA for 1776 it says it is Westmorelnad county formed from Bedord. Greene county was Monongalia county, Virginia from 1775-1780. It was Bedford then in 1773 Westmoreland and then 1775-1780 it was Monongalia county, Virginia and part Ohio county, Virginia then Washington county in 1781.Before that iw was West Augusta district of Virginia. I think you probably got the counties from Washington being from Westmoreland being from Bedford, etc.

    Great job though!!

  4. Fantastic tool. Best thing next to popcorn. Just a suggestions. The ability to show the current county lines under the searched year county lines but with a different line color.
    Thanks for the tool!

  5. Just found your blog this morning and am blown away – just what we can use! Re-posting A LOT!
    Wouldn't it be nice to be able to map ancestor's birthplace (baby icon)and each town they moved to (with arrows)ending with the cemetery (cross icon) they're buried in? Just saying…

  6. In response to issues encountered with Maine, Minnesota, and Oregon,

    Maine, Minnesota, and Oregon, which had partial-loading issues, are now functional. All 50 states are completely loaded now.

  7. In response to June Higgins' bug using Firefox,

    There was indeed a bug with the "Go" button that was specific to Firefox! Thank you much for reporting it.

    I have fixed the error and tested it with the following web browsers' latest production versions: Firefox, Chrome, Internet Explorer, Safari (including iPad version).
    Note: the map tool also works on Blackberry and the iPhone, but for proper functioning you must choose "View web version" from the bottom of the page.

    Thanks again, Jen, and I hope you get get use from the map tool!


  8. Just got a notice about your site. It looks great, but I can't get any action after clicking on "Go." Does it work with Firefox (Mozilla) browser?

  9. Randy,

    Great tool! I am map junkie and love history, so this is a great amalgamation. I have used AniMap for years, but always found it a bit klunky and with modern context. You have done a great job.

    One request I have; As with most maping software, the counties end at the state political divide.

    It would be awesome to get the adjacent state's counties included in the map.

    Case and point: Missouri Territory ~ 1820-1830. The modern county of Lawrence County, Arkansas owned a large portion of the southern edge of the current state of Missouri.

    The northern edge of the Lawrence County, Arkansas Territory line, was 30 miles north of the current Missorui state line.

    So for persons looking for a county seat at this early developing area, they would actually need to search in Arkansas, not Missouri.

    I'm interested in the underlying method you used. Can you share the ideas behind your process?

    -Again – great work – thanks a bunch.


  10. Randy, the "Virginia" workaround does work. Had to go to time 1777 to get the map to show the three Counties into which the District of West Augusta was split in 1776 (Monongalia, Yohogania, Ohio). And it showed the bounds in present SW Penna. that VA believed was part of VA. Excellent product — and glad to see the abbreviated citation to Hening's Statutes at Large in the popup.

    There could be an explanation in the tool regarding how to find the citations . . .

    Thanks :D

  11. In response to Geolover's question on Morgantown, WV 1774,

    You've hit a tricky one, but here's how to make it work!

    Because WV didn't exist in 1774, and it was part of VA, what you have to do is "trick" my map tool into showing VA counties for 1774.

    To do this, just type VA and 1774, and Virginia Counties will appear. Then, drag or pan the map manually over to present-day Morgantown, WV, and you will see the "Virginia" counties as they existed then. (In this case, it shows "W. Augusta Dist." and provides more detail if you click the map near Morgantown, WV).

    So, that's the workaround when you want to show historical counties from a state that didn't exist in the year in question.

    Thanks for the puzzle! :)

  12. Tried Uniontown, PA 1775 again today. Boundaries drew okay (for PA) and did get popup.

    Tried Morgantown, WV, 1774, no boundaries. Not interested in Morgantown, VA, an entirely different locality NE of Richmond.

    How do I get the boundaries for VA's view of SW Penna. and northern WV – showing old Monongalia and Yohogania Counties covering part of present day PA? Tried just Monongalia (no State designation); the pin was in the right area but could not get boundaries.

  13. In response to a couple of anonymous comments related to Oregon and Minnesota,

    Yes, you are correct that there are some partial-load problems with those two states that I am trying to address with the Google Fusion Tables teams.

    As far as I know, this means there are three outstanding states with issues: Maine is not loaded at all (complex coastal polygon problem) and Minnesota and Oregon are only partially loading.

    Let me know if anyone sees persistent problems with any other states please. (Try hitting F5 and refreshing your browser and trying the search a couple of times before concluding a problem though please, as the Google fusion tables are still an experimental feature and can be intermittent at times.)

    Thanks everyone for your great support and interest!


  14. In response to Geolover's comment,

    Thanks for trying out the tool. I checked SW PA around Uniontown in 1775, and that drew fine for me. The info window showed Westmoreland County.

    Please let me know if you are still seeing an issue there.

  15. Randy,

    I've tried to use it this morning, and nothing happens. No boundaries, no map of the specific place.

    A temporary problem (I hope!).

    Randy Seaver

  16. There's also a problem with West Virginia, which didn't exist until about 1865. Typing Wheeling, WV will put a pin in the right location, but no counties will appear unless the year is after 1865. You can input "Virginia" and get the historical counties then zoom in to the current West Virginia areas, but you can't directly input a place.

  17. In response to bgj's comment,

    Thanks for the comments; I'm glad you've found the tool to be useful, and hope you keep coming back!

    Regarding your comment in which you stated "I ran a search for James County, TN 1880 and was pointed to a place in Georgia near Dalton. James County, TN was formed in 1871 and dissolved in 1920."

    I should clarify that the Place you type into the box needs to be a PRESENT-day city, town, or county. So, for example, if you type "Tyner, TN" and "1880" for the year, the map will take you to the correct place: you can click on the map there and it correctly shows James County, effective date of 2/18/1871. (I don't know if Tyner was the right town name you were looking for, so just substitute the right town name in my example.)

    By the way, the Place box uses a standard Google Maps geocoding engine, therefore you can even use present-day street addresses, road names, points of interest, and the like, and then just type in the correct historic year to see what county that address or road was located in back then. So, in this example, you could type "Silver Oaks Cemetery, Tyner, TN" or "Old Lee Highway, Tyner, TN" together with the year 1880, and it will take you and show James County's boundaries.

    (Of course, this doesn't account for addresses or road names that may have changed, so if you suspect that, then just start with the right current-day town or city name.)

  18. I have had problems with Oregon towns such as Parkdale and Wasco in 1920 and 1930. Only a few of the Oregon counties appear. I'm using Firefox 4.0.1. Other states I've tried have worked fine.

  19. Neat tool. Did have problem showing boundaries in SW Penna. 1775 (typed in Uniontown, PA). When I clicked inside a County boundary I got no popup. Instead, the engine zoomed in or out a notch (depending on my previous zoom-level click). Using Firefox 3.5.15 on WinXP.

    Thanks for your many practical efforts :)

  20. In response to an Anonymous comment regarding not working on Android,

    If the map is not functioning on certain mobile devices, try scrolling to the bottom of the page and clicking the "View web version" link. (I haven't tested this on Android or the iPhone, but I have checked it on my Blackberry Torch browser, and it enables the map to function.)

  21. Randy,
    Thanks for fixing Louisiana! Yes, I know all about parishes (I grew up in Louisiana, where most of my family still resides)! I thought that might be the issue. Thanks for fixing. Great tool!

  22. In response to Claire Bettag's comment,

    Thanks for the catch on Louisiana; I've fixed it, and it is working now!

    As you may know, Louisiana is unique in that it uses Parishes in the same way that most other states use Counties (see ). The problem was that I only had Counties loaded, and not Parishes, which were created March 31, 1807 by the territorial legislature. So now, if you type 1807 or prior you will see Counties, and if you type 1808 or later you will see Parishes.

    Also, to solve similar issues, I've made fixes to South Carolina and North and South Dakota, as follows:
    – In South Carolina, Districts were used instead of Counties from 1801-1868, inclusive. If you type a year in that range, you will see Districts; before or after that range, you will see Counties.
    – In North and South Dakota, if you type a year 1889 or prior, you will see Counties from the combined Dakota Territory

  23. In response to Derek Wood's comment,

    Thanks for the positive feedback. As of today, Massachusetts and Alaska are now included! So, the only state not yet included is Maine. (Unfortunately, Maine's complex polygons along the coast are causing some problems. Due to this, the part of Massachusetts prior to 1820 that is in present-day Maine is also not included in Massachusetts)

  24. Randy,
    Great job. I'm sure I will use this over and over as I do my genealogy research. Also thanks to Dick Eastman for pointing this site out.

    I understand this is still a beta version and would like to note a problem I experienced. I ran a search for James County, TN 1880 and was pointed to a place in Georgia near Dalton. James County, TN was formed in 1871 and dissolved in 1920. Hope this helps in your progress with the beta testing.


  25. Very, very nice work Randy. I have bookmarked this and will use it often. There appears to be a problem with the data for Minnesota. Not all of the county boundaries displayed on any search I did.

  26. A really great tool. But the GO button does nothing on my Android phone's default browser. Shucks.

  27. Randy, This is a wonderful tool. But I cannot get it to work for Loiuisiana — anywhere, anytime. I do not get the "this is beta" message that I get when I try MA, but nothing happens. What's the story?

    Claire Bettag

  28. Great work.

    Do not know how to deal with towns that disappear or have another name in later years elsewhere in a state such as Jonesville, McIntosh, GA – the historical marker in GA placing it 0.6 south near South Newport not in Carrolton County as now.

  29. Randy – wow, this is awesome! Really, great work. Much more user-friendly than the Town/County Search at rootsweb (old habits die hard). I'll be using this plenty.

    I don't know about AK, but I'm guessing MA and ME are tricky because of how far back in colonial history they go and how their historical counties overlap with contiguous states?

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