Practice making a small map of the United States. Adapted from many resources, including this base map. Process described here with additional references.
Modified http://d3js.org/d3.v3.min.js to a secure url
Modified http://d3js.org/topojson.v1.min.js to a secure url
https://d3js.org/d3.v3.min.js
https://d3js.org/topojson.v1.min.js