SunlightLabs API
Sources of Place-Related Data
The basic zipcode data tying cities to states, latitudes, longitudes and timezones come from Civic Space free zip code DB. This contains 43,000 zip codes for the continetal United States, Alaska, Hawaii, Puerto Rico, and American Samoa. We must stress these data are old! They come from census data from 1999, 2000, and 2003.
These data are hosted localy at the labs and are not actively being maintained. However, if you have more up-to-date zipcode data we would love to hear from you.
Additional data, which ties congressional districts to cities and zipcode comes from http://www.echoditto.com/zip2rep. These data were released publically in August 2006 but it is not at all clear the data when these data were collected. As with the zipcodes aboves, these data are hosted locally at the labs and are not actively being maintained.