A choropleth map visualizes county-level poverty rates across the United States, using a blue sequential color scale and a legend with percentage tick marks. County boundaries are drawn with SVG paths via `d3.geoPath`, colored by data from a CSV file, and overlaid with white state lines from a TopoJSON mesh. The implementation loads both datasets with `Promise.all`, applies the `d3.scaleThreshold` color scheme, and adds interactive tooltips on each county path.