This example shows a choropleth map of US states colored by a numeric rate value, using a green color scale from d3.scaleThreshold. The map is centered on the US using the geoAlbers projection and rendered with d3.geoPath in SVG. State boundaries come from US Atlas TopoJSON data, with interiors highlighted via topojson.mesh. The React app loads state rate data from a TSV file and maps each state’s rate to its fill color. Graticules and a smooth sphere background complete the polished cartographic style.