US County Map - Basic

<!DOCTYPE html>
<meta charset="utf-8">
<style>
body{
  font-family:Roboto;
  font-size: .6rem;
}
.state-border {
  fill: none;
  stroke: #000;
  stroke-width: .5px;
}
.counties {
  fill: #eee;
  stroke: #bbb;
  stroke-width: .5px;
}
.counties path:hover {
  fill: #ddd;
}
.county-border{
  fill: none;
  stroke:#fff;
  stroke-width:2px;
}
.county-name text{
  text-anchor: middle;
  pointer-events:none;
}
</style>
<body>
<svg></svg>
<script src="https://d3js.org/d3.v4.min.js"></script>
<script src="https://d3js.org/topojson.v1.min.js"></script>
<script src="https://vizjs.org/viz.v1.2.0.min.js"></script>
<script>
var width=960, height=1800;

d3.json(viz.maps.uscountyurl, function(error, uscjson) {
  if (error) throw error;	
  
  viz.maps.uscounties=uscjson;

var counties = viz.uscs()
	.state('NJ')
	.height(height)
	.width(width);
  
  d3.select("svg")
	.attr("width",width)
	.attr("height",height)
	.call(counties);
});

// adjust the bl.ocks frame dimension.
d3.select(self.frameElement).style("height",height+"px").style("width",width+"px");  
</script>

Modified http://vizjs.org/viz.v1.2.0.min.js to a secure url

https://d3js.org/d3.v4.min.js

https://d3js.org/topojson.v1.min.js

https://vizjs.org/viz.v1.2.0.min.js