This choropleth visualizes U.S. county-level poverty rates for 2021, with each county colored along a threshold scale of green shades; hovering reveals a tooltip with the county name and its exact percentage. The map is rendered as SVG using D3 v7’s `d3.geoPath` and TopoJSON `topojson.feature` to draw county boundaries, while a separate mesh path outlines counties lacking data. Poverty data is loaded from a CSV via `d3.csv`, and the color legend is generated with the d3-legend library. The visualization also includes a title and uses a linear scale to position the legend.