This choropleth map visualizes poverty estimates across US counties in 2021, using a red sequential color scale to encode rates. The map renders county boundaries as SVG paths via `d3.geoPath` and TopoJSON, with white state borders overlaid for context. Hovering over a county triggers a CSS tooltip displaying the area name, state, and poverty value, while the county highlights in steel blue through a class toggle. A legend with an `axisBottom` scale maps thresholds from 0 to 50 percent, and data loads from an external CSV with `d3.csv`.