View Google Maps with historical county boundary lines with this free tool.

County boundaries change over time and this tool built on Google Maps will help you make sure you're searching in the correct county for the place and historical years you're researching.

Have a genealogy blog or website? Create your own custom link to this Historical U.S. Counties Map for any year and place!

  1. Type any PRESENT-day place or address in the "Search places" box above the map*
    OR: Zoom into your place of interest on the map
  2. Type any HISTORIC date or year in the "As of date" box and click Go! The date must be in the format M/D/YYYY or can be just a 4-digit year.
    Historical county boundaries will draw, and an information pane about the county of interest will appear at the bottom of the map. The information pane lists the historical county name at the red dot, and provides details on the latest boundary change as of the date you typed, including reference to the particular statute that triggered the change. The latitude and longitude for the red dot is also displayed.**
  3. Check the "Show historical county labels" checkbox in the lower left corner of the map to see the names of the historical counties on the map
  4. Optionally, check the "Also show present-day county lines" checkbox in the lower left corner of the map to see present-day county lines (thin red lines) overlaid on top of historical county lines (thicker brown lines)
  5. Optionally, check the "Show chronology..." checkbox in the lower left corner of the map to see a complete listing of every county boundary change for your chosen location from the date you typed back in time to original county formation
  6. Click the "⊕ Locate" button in the upper right corner of the map to use your current location***
  7. Subscribe in the top header to receive notification of tool updates and usage tips
* You can also type in GPS coordinates in decimal degrees into the Search places box. For example, type -105.25, 40 for Boulder, Colorado.
** All information is reported based on the location of the red dot on the maps; to move the red dot, click the map
*** The "Locate" button will be more accurate on smartphones and other devices containing a GPS; desktop browsers typically show an approximate location

How do you see Google Maps with historical county lines? Just follow the quick steps above and you will see the historical county boundary lines for anywhere in the U.S. displayed on a fully-interactive Google Map.

Answer questions such as:
- What county was this present-day address located in as of this historical date?
- What county was my ancestor's farm in as of this historical date?
- Which county's archives or court house might have records for the time period I am researching?
- What county were these GPS coordinates located in at this historical date (see * above)?
Plus many other topics where knowing historical counties may be important, such as education, genealogy and historical research

Looking for PRESENT-day county boundaries on Google Maps? Here it is: County Lines on Google Maps.

- Coverage includes all 50 US states, from as early as 3/4/1629 through 12/31/2000. For present-day county lines use the County Lines on Google Maps tool.

  • The Search places box uses a standard Google Maps geocoding engine, therefore you can type PRESENT-day street addresses, road names, points of interest, and GPS coordinates (see * above) to see what county that location is part of
  • NEW! Some counties or regions were claimed by more than one jurisdiction in some historic years. When this is the case, an "Overlapping jurisdiction" button will appear at the bottom of the map enabling you to toggle to the other jurisdiction's information.
  • The map layers from which this information is extracted are very large, so it may take several seconds to finish drawing
  • Note that typing an address will zoom in the map very close, whereas typing a city or county by itself will show you a map with a wider view
  • Disclaimer: While the number of decimals in the latitude and longitude displayed for the map marker imply a positional accuracy of within a few feet, note that Google Maps is not inherently that accurate, and therefore this tool should not be used for legal purposes or anything beyond entertainment value.

- 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 this tool under the Creative Commons license shown on the bottom of the linked page.
- US Census Bureau

Try the new Section Township Range on Google Maps tool here!

Help improve this tool. Please comment.
Historical U.S. County Boundary Maps tool, v 4.9 ©2019 Randy Majors

Also, check out the AncestorSearch using Google Custom Search tool on this website to build a Google search that is optimized to find web pages mentioning your ancestors! The search returns a more focused set of results by using advanced Google search techniques including exact phrases, forward and reverse name order, alternate name spellings, logical operators, and so on.

Have a genealogy blog or website? Create your own custom link to this Historical U.S. Counties Map for any year and place

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