This choropleth map shows the percentage of adults with a bachelor’s degree or higher across U.S. counties, using a sequential YlGn color scale. The React app loads county, state, and nation boundaries from a TopoJSON file and education data from freeCodeCamp’s CDN, then renders them as SVG paths via `d3.geoPath`. County colors are assigned by looking up each county’s FIPS code in a Map, with white fill for missing data. State outlines are drawn as a mesh overlay, and the map is generated with `d3.json`, `topojson.feature`, and `scaleSequential`.