You might have not known that the geodata package for Map Chart includes not only country maps, but also detailed county maps for all U.S. states.
Using county maps
The county map files are located under
region/usa subdirectory of the geodata package.
If you are not familiar with the geodata package and how maps are loaded into Map Chart, please make sure you check out this section.
Normally, you would load the geodata definition direct from the geodata package's root:
import am4geodata_worldLow from "@amcharts/amcharts4-geodata/worldLow";
Then you would access the map definition using variable
It's not that much different with county maps, except you need to use subdirectory references both in referring to the files and variables:
import am4geodata_region_usa_caLow from "@amcharts/amcharts4-geodata/region/usa/caLow";
And the variable with the loaded map definition would be
Each map in the U.S. county map directory is identified by the state's ISO two-digit code (in lowercase).
In the above example we were loading a map for California's counties, since that state's ISO code is
As with all maps in amCharts 4, county maps come in two flavors: low-detail and high-detail. They are suffixed with
US-wide county map
There's one additional map in the directory as well:
As you've probably guessed, it has counties for all the states on one single map.
Beware though, it's huge, so, unless absolutely necessary, don't throw that onto your users.
Below, you will find an example of a live map displaying California's counties: