This map displays EPA air quality monitoring sites across the United States as blue circles overlaid on a geographic outline of the states. The visualization uses React to render SVG elements, with D3’s `geoAlbersUsa` projection and `geoPath` to draw state and interior boundaries from a TopoJSON US Atlas. Data is loaded via `d3.csv` from a GitHub-hosted file, with point locations plotted by longitude and latitude. A square root scale (`scaleSqrt`) maps AQI values to circle radii, though the current radius is fixed at 5 pixels.