Shapefiles (.shp) are used in GIS systems to represent shapes like building and parcel boundaries, municipal, county, state, and country boundaries, landmarks, and more.

For the DemocracyMap project, I was introduced to shapefiles by Phil Ashlock at OpenGovWest, Seattle in 2010. I had falsely assumed government was structured similarly throughout the nation. In California, there is a pretty clear relationship between city > county > state. But several other states have varying structures in place, even within the same state.

Google Maps is popular implementation of GIS that most people are familar with. But, there are many other tools that can be installed on your computer or company server provide features like loading, viewing and manipulating shapes, and sharing the data in several different formats. Formats such as GeoJSON, and Google's KML are becoming more common for using GIS in web-based systems.

So, onto the point of this note. I've been looking for shapefiles for local municipalities as part of the DemocracyMap effort to enable a comprehensive lookup of all public officials, the governing bodies that they may belong to, and the agencies and jurisdictions for which they represent.

Sources

I found the following sources helpful:

http://swdb.berkeley.edu/data.html - CA Shapefiles http://blog.apps.chicagotribune.com/ http://open.blogs.nytimes.com/2010/07/01/introducing-the-districts-api/ - NY Times App http://github.com/dwillis/NYT-Districts-API-Demo http://www.vote-smart.org/search.php?search=95688 - A good working example of state level, but missing county/city/special districts GIS Tools & Talent SimpleGeo Polymaps is a great tool, developed by Stamen and Simple Geo DevelopmentSeed does a bunch of great GIS work OpenPlans and their OpenGeo division Geoserver