This visualization displays COVID-19 deaths per million in the United States over time as a date histogram, with each bar colored using a sequential blue scale to encode magnitude. The data comes from a CSV file loaded via `d3.csv`, and the chart uses `d3.bin` with `timeMonths` thresholds to aggregate cases into monthly bins, `d3.sum` to calculate totals, and `d3.scaleTime`/`d3.scaleLinear` for axes. React manages hover interactions, showing a value label above the selected bar.