This interactive map of the United States visualizes county-level population data as circles. It uses the D3.js library (v5) to render an SVG graphic, employing `d3.geoPath` and a map projection sourced from a TopoJSON file. County centroids are calculated with `d3.geoCentroid` to position each circle. The visualization reads population figures from a local CSV file, and includes a zoom feature via `d3.zoom` for user interaction.