How to Make Choropleth Maps in D3

You’ll notice that South Carolina and Missouri have no fill color: it appears that the data is not formatted correctly for these states. If this were a real visualization, you would need to go in and correct that by hand (as you often do when working on projects like this). There is also a strange shape in the bottom left caused by some stray paths included in Wikipedia’s SVG file. You can delete them in the SVG in your main HTML file.