This demo displays US state boundaries using the custom geoAlbersUsaTerritories projection, which extends the standard Albers USA projection to include US territories. The map renders as an SVG, with state interiors drawn as a mesh and land areas filled in teal. Data comes from the US Atlas TopoJSON file, processed with `feature` and `mesh` from topojson. The code leverages React hooks to load data asynchronously and d3’s `geoPath` and `geoGraticule` to generate the geographic paths.