This choropleth map of US states uses a green color scale to encode population, with hover interactions highlighting states and displaying their name and population via a tooltip. Built with D3.js, it renders geographic features using `d3.geoPath` and a GeoAlbers USA projection, while `Delaunay` from D3 creates invisible Voronoi cells for reliable hover detection. Population data comes from a CSV of US Census Bureau estimates, and state shapes use US Atlas TopoJSON data.