I wanted to explore the relationship between states and the railroads in them. For each state, I've acquired the number of miles of railroad in it and also the number of square miles it takes up. To compare the data in an appropriate way, I've normalized it by dividing the number of miles of railroad in the state by the number of square miles and then multiplied it by one thousand. This gives us a normalized value of "miles of railroad per 1,000 square miles of area". Each state is then colored based on a linear color scale given its miles of railroad per 1,000 square miles of area. Finally, I found a geofile for all railroads in the USA and drew them on the map as well.