This bar chart displays total firearm background checks by U.S. state for September 2023, with each bar stacked to show the breakdown between handguns, long guns, other firearms, and multiple-gun purchases. The chart aggregates monthly data from the NICS dataset, filtering out territories. Built with D3 v7 and d3-rosetta, it uses `scaleBand` and `scaleLinear` for axes, appends stacked rect elements per gun type, and includes a legend showing color-coded categories.