This example shows how to build a bar chart with React and D3, displaying the top 10 countries by population from a 2019 UN dataset. The chart renders SVG rectangles, with countries on the y-axis using `scaleBand` and population values on the x-axis using `scaleLinear`. The data is loaded asynchronously via `d3.csv`, and React state manages the loading and storage of the parsed dataset. The visualization demonstrates a clean separation of concerns, where D3 handles scales and data loading while React manages component rendering and state updates.