Election Data Services maintains a nationwide database of district boundaries and offers congressional and legislative district boundary files for geographic information systems (GIS). The database includes representative districts for the United States Congress as well as districts for the upper and lower houses of 49 state legislatures, Nebraska's unicameral legislature, and the Council of the District of Columbia.
District boundaries are based on the census TIGER/Line® files and are plotted from x,y coordinate pairs (vertices) expressed as NAD 83 latitude/longitude, decimal degrees. Current boundaries are for congressional and legislative districts redrawn with demographic and geographic data from the 2000 decennial census.
District boundary files are available in five GIS formats and are priced at 10 dollars per district and are available for individual states or for the country as a whole. The minimum price is $95 per order. Prices for the nationwide files have been discounted substantially. The price of the nationwide file of congressional district boundaries is only $2,000, while the nationwide file of state legislative district boundaries is $10,000.
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District Boundary File Formats
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| Format |
GIS System |
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AGF
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Atlas GIS geographic file |
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BNA
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Atlas ASCII for Atlas GIS |
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MIF
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MapInfo Interchange Format |
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SHP
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ESRI shapefile for ARC/INFO and ArcView GIS |
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TAB
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MapInfo for Windows |
Also available is a nationwide file of congressional district boundaries that have been “generalized.” The price of the generalized congressional district boundaries is only $1,000. Generalized boundaries may be suitable for maps where fewer details are required. File sizes of generalized district boundaries are significantly smaller.
To order a district boundary file or obtain price information for individual states, please contact sales@electiondataservices.com or call Kimball Brace at 202–789–2004.
