This choropleth map visualizes the percentage of residents with a bachelor’s degree or higher across U.S. counties. Each county is filled with a color from the d3.schemeGreens palette, mapped through d3.scaleThreshold to the education data. The map uses d3.geoAlbersUsa projection with d3.geoPath to render county boundaries from TopoJSON data, while a color legend built with reusable D3 code shows the scale. The visualization also supports zooming and panning via d3.zoom.