This network graph visualizes the hierarchical relationships between US states, regions, and counties using a force-directed layout. The D3.js v7 code builds nodes and links from a nested data structure, employing `d3.forceSimulation`, `d3.forceLink`, `d3.forceManyBody`, and `d3.forceCenter` to position elements. Nodes are rendered as SVG circles with drag functionality, while links appear as black lines. The visualization distinguishes entity types through CSS classes, with a light yellow background and clear text labels.