A demo of TopoJSON on a U.S. counties shapefile from the census bureau using d3.geo.albersUsa. The same TopoJSON file can also be used to show counties.
forked from mbostock's block: U.S. States TopoJSON with no decoration
https://d3js.org/d3.v3.min.js
https://d3js.org/topojson.v1.min.js