This example visualizes the distribution of infectious diseases in 1968 using a sequential bar chart, with each bar’s height and color intensity encoding the number of infections. The chart employs a sequential color scale based on ColorBrewer’s OrRd scheme, mapping values from 0 to 150,000, and includes a legend generated with the d3-legend library. The visualization is rendered as SVG using D3 v6, with axes, labels, and a dark background for contrast. The data, simplified from the CORGIS Global Development dataset, is loaded from a CSV file, and the chart uses `d3.scaleBand` for the categorical x-axis and `d3.scaleLinear` for the quantitative y-axis.