Online U.S. Atlas of Historical County Boundaries

(The article below is from Dick Eastman’s Online Genealogy Newsletter. Credits are given at the end of the piece.)

One of the more useful tools for genealogists is the Atlas of Historical County Boundaries created by the Newberry Library in Chicago. When I first started in genealogy, one of my biggest frustrations was trying to find records of ancestors in the county where they lived. Many genealogical records are created by counties. In many cases, I knew the town where they lived and I also knew what county the town was in. Yet I couldn’t find the records that normally are kept in county courthouses, such as probate records or the deeds of land transfers.

As I gained more experience, I soon learned that the problem was mine. I had looked in the country records for the county lines of today. In many cases, the county lines had moved over the years, even though my ancestors had not moved an inch. Once recorded at the county courthouse, records normally remain at that courthouse forever, even if the county lines are redrawn later and the property or the town in question is then “moved” to a different county.

For instance, if your ancestor lived in the town of Smallville in Washington County when the information was recorded at the courthouse and later the county lines were redrawn so that town of Smallville and your ancestor’s location were later in Lincoln County, you still need to look for older records in the Washington County courthouse. Existing courthouse records usually are not moved to a new courthouse when county lines are redrawn.

Experienced genealogists all know that you need to look in the county courthouse for the correct county as of the date the records were filed. But how do you find the correct county lines as of the date(s) your ancestors lived there and left records? You can find several books at well-equipped libraries that will provide that information. However, the Atlas of Historical County Boundaries will provide the information as well without requiring the time and travel expenses of visiting a well-equipped library. Yes, you can find the information without leaving home. The Atlas of Historical County Boundaries web site is available FREE of charge. You can even download the files to your own computer and save them or use them as you please. The online atlas has been available for years but I find that many genealogists are unaware of its existence and do not know how useful it can be.

With the Atlas of Historical County Boundaries, you can view records on a per state basis, an interactive map, or choose the time slots that best meet your requirements. You can search by location or by time or by both. To use the web site for the first time, select a state from the map on the site’s home page to view all of the Atlas’ content related to that state, including shapefiles, chronologies, and metadata. If you cannot quickly find the information you seek, narrow the search by choosing from the available list of options. Probably the most useful option for genealogists is to display maps by dates.

A lot of helpful information about the site can be found on the “Using the Atlas” page at:

This is a web site worth bookmarking. You probably won’t need to use it often but, if you do ever have a need, it can supply the information you seek quickly.

The Atlas of Historical County Boundaries is available at the Newberry Library’s web site at:

Randy Majors left this comment to the above blog posting:

Your readers may also find this free tool I built based on the excellent Newberry source in your article:

Simply type a PRESENT-DAY address, city or place, then type any HISTORICAL date, and the historical county boundaries from that date will appear overlaid on a familiar Google Map (including satellite view). Then optionally overlay research locations on the map such as courthouses, cemeteries, churches, and libraries, and link right to them for more information. It also displays the statute that formed the boundary, and optionally animate the change in boundaries over time for that location. Over 60,000 visits to this tool I think largely due to its simple usability.

The above article and comment are from and are copyrighted by the Eastman’s Online Genealogy Newsletter at Many thanks go to Dick Eastman for his continued support of the genealogy world.

As a reminder, the best PC program ever that shows county boundaries over time has been AniMap. It is still for sale as version AniMap 3.0.2 at the GoldBug Software web site:
And remember, the Monterey FHC has a copy of AniMap that can be used inside the FHC.

But, for sure, the above ONLINE and FREE options can be used at home, now, as we need.

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