This file shows how to use the albersUsa projection from d3-composite-projections. In this case, the example (and projection) is copied directly from the d3 projection, but adding the borders a the composed zones.
<!DOCTYPE html>
<meta charset="utf-8">
<style>
.land {
fill: #222;
}
.county-boundary {
fill: none;
stroke: #fff;
stroke-width: .5px;
}
.state-boundary {
fill: none;
stroke: #fff;
}
</style>
<body>
<script src="http://d3js.org/d3.v3.min.js"></script>
<script src="http://d3js.org/topojson.v1.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/d3-composite-projections/0.3.5/albersUsa-proj.min.js"></script>
<script>
var width = 960,
height = 500;
var projection = d3.geo.albersUsa()
.scale(1000)
.translate([width / 2, height / 2]);
var path = d3.geo.path()
.projection(projection);
var svg = d3.select("body").append("svg")
.attr("width", width)
.attr("height", height);
d3.json("/d/4090846/us.json", function(error, us) {
svg.insert("path", ".graticule")
.datum(topojson.feature(us, us.objects.land))
.attr("class", "land")
.attr("d", path);
svg.insert("path", ".graticule")
.datum(topojson.mesh(us, us.objects.counties, function(a, b) { return a !== b && !(a.id / 1000 ^ b.id / 1000); }))
.attr("class", "county-boundary")
.attr("d", path);
svg.insert("path", ".graticule")
.datum(topojson.mesh(us, us.objects.states, function(a, b) { return a !== b; }))
.attr("class", "state-boundary")
.attr("d", path);
svg
.append("path")
.style("fill","none")
.style("stroke","#000")
.attr("d", projection.getCompositionBorders());
});
d3.select(self.frameElement).style("height", height + "px");
</script>