Working with data collected by the Atlas Project, we developed what may be the largest gallery of political maps in US history. The collection of over 1,300 maps served as a major resource for progressive campaigns in the 2012 election cycle.

We started with a list of 108 spreadsheets of electoral, political, and socio-economic data that Atlas offers to its clients. Then we built a mapping UI that lets those clients visualize the datasets on a map and overlay appropriate contextual layers for comparison.

Of the 108 datasets, some yielded multiple (hundreds) of maps. Each of these maps were categorized into TileMill projects based on their unique style requirements, for instance a project for election results as a percentage choropleth, and a scaled marker style for contextual overlays. We developed a workflow to convert Excel spreadsheets to neatly packaged SQLite files, ready to be mapped in TileMill, which we then processed into MBTiles and uploaded them to MapBox Hosting.