This choropleth map visualizes U.S. state populations, filling each state with a blue color scale from light to dark based on its population value. It uses d3.geoAlbersUsa for projection and d3.geoPath to render TopoJSON state and nation outlines from the us-atlas dataset. Population data is loaded from a separate text file and parsed into a lookup table, with tooltips appearing on hover. The visualization is built with D3 v7 and rendered as SVG.