This example displays the contiguous United States color-coded by Census region: the Northeast, Midwest, South, and West. Each regional group of states is drawn as a separate path element, with the colors defined in CSS. The visualization uses the D3 library’s `geoPath` to render geographic data and the TopoJSON `feature` and `merge` functions to combine the US states dataset with its geometries. The map is rendered as an SVG, and the data is loaded from the `us-10m.v1.json` file.