This stacked bar chart visualizes population data for U.S. states, with each bar segmented by color to show the proportional contribution of different data categories. The visualization uses a horizontal layout where bar lengths are scaled linearly against population values. Built with the d3 library, the chart employs `scaleLinear`, `scaleBand`, `stack`, and `flatRollup` to process and arrange the data. The color legend supports interactive hover effects, allowing viewers to highlight specific categories within the stacked bars. Data comes from a CSV file loaded directly from a GitHub gist.