This example visualizes the adjacencies of 49 U.S. states and the District of Columbia as a node-link diagram, with each state represented as a circle and each shared border as a connecting line. The visualization uses D3’s force layout to position the nodes, applying charge and link distance parameters to simulate a physical network. Rendered as an SVG, the code loads data from a JSON file containing node names and edge indices, then draws circles and lines whose positions update on each tick of the force simulation.