Contents of files from Harvard Geospatial Library
1. dofiles - executable files to create the county-level data sets I
   will use. 
2. datafiles - contains the county-level stata files created from merging the dbf
   files from the ArcGIS shapefiles.
3. longform - these tabulations are based on the subset of census
   respondents who were given the long form of the questionnaire.
4. historical - these tabulations are from the Harvard library
   historical files of the census. 
5. Note: these are ArcGIS shapefiles to create maps. You can make maps
   in stata (see ch2000_counties.do) using the shp2dta
   command. Alternatively, you can grab the .shp, .shx, .dbf files and
   load them directly into ArcGIS. Note that in the ArcGIS terminology a
   shapefile refers to the collection of these three file types.