This scatterplot visualizes the relationship between population and GDP per capita for U.S. cities using D3.js v6. The SVG-based chart plots each city as a steel-blue circle with a black stroke, positioned along linear scales for both axes. The code loads data from a GitHub-hosted CSV file, converts the population and GDP values to numbers, and renders axes with formatted tick labels. Interactive tooltips appear on mouseover, displaying each city's name, population, and GDP per capita. The visualization employs d3.csv for data loading, d3.scaleLinear for mapping, and d3.axisBottom and d3.axisLeft for coordinate axes.