A demo of TopoJSON using a single file that contains county, state and country boundaries. This example uses topojson.mesh
to extract separating lines between states and counties from the geometry collections.
To see the resizable nature of this image, check out this gist live at: http://bl.ocks.org/harlantwood/raw/6900108/.
This is a fork of https://gist.github.com/mbostock/4136647, which you can see live at http://bl.ocks.org/mbostock/4136647. I reverted to an earlier version of the gist, as the feature that I was interested in -- dynamic resizing of the image on browser resize -- seemed to be removed in the later versions.
I found the original gist when searching on this topic via this post: .