This bar chart displays COVID-19 case counts for the top 20 countries, ranked by their reported infections on January 28, 2020. Using React with D3 v5, the visualization renders SVG rectangles scaled by population data from a CSV file, with D3’s `scaleBand` and `scaleLinear` mapping country names and case values. Axis ticks and labels are generated manually via `.map()` and React elements, while the data is loaded asynchronously with `d3.csv`. The chart shows a horizontal bar layout with green rectangles and red gridlines, highlighting comparative case volumes across countries at that early pandemic date.