This visualization shows the cumulative number of COVID-19 vaccinations in the United States over time, plotted as a green line with individual data points. It uses D3 v7 to load a CSV dataset from GitHub, parse dates, and render an SVG chart with time and linear scales. Tooltips appear on mouseover via D3 event handlers, displaying the exact date and vaccination count, while rotating x-axis labels and axis generators like `d3.axisBottom` and `d3.axisLeft` structure the timeline.