This example demonstrates how to build a bar chart using React to render SVG elements and D3 to load and parse data. The visualization fetches population data from a CSV file via `d3.csv` and displays it as a series of rectangles, with React’s `useState` and `useEffect` managing the asynchronous data loading. D3 v6 and React 17 are used together, with the chart showing a loading message until the dataset is ready. The SVG-based chart currently renders blank rectangles without positional or size encodings, highlighting the integration of React’s declarative component model with D3’s data utilities.