Jeffrey B. Lewis: “This site provides digital boundary definitions for every U.S. Congressional District in use between 1789 and 2012. These were produced as part of NSF grant SBE-SES-0241647 between 2009 and 2013. The current release of these data is experimental. We have had done a good deal of work to validate all of the shapes. However, it is quite likely that some irregularities remain. Please email [email protected] with questions or suggestions for improvement. We hope to have a ticketing system for bugs and a versioning system up soon. The district definitions currently available should be considered an initial-release version…”