This visualization maps H1B petition locations across the United States, with circles colored by petition year. An interactive legend on the right filters the map by year when hovered, dimming non-matching data points. The visualization uses React for component structure, D3’s `geoAlbers` projection and `geoPath` for rendering US state boundaries from TopoJSON data, and `scaleOrdinal` for color encoding. City coordinates come from a CSV dataset, rendered as SVG circles with opacity controls for the hover interaction.