A line chart displays the number of reviews per day for multiple US states, with each state represented by a colored line. A legend allows clicking to highlight or fade individual states. Built with D3 v5, the visualization uses `d3.nest`, `d3.line`, `d3.curveBasis`, `scaleLinear`, and `scaleOrdinal` with `schemeCategory10`. Data is loaded via `d3.csv` from a VizHub dataset. SVG rendering includes axes, gridlines, and a title.