The County and City Data Books provide online access to a range of city, county and state statistical data. Duke's online service provides access to data from the 1930s to the 1970s.

The data for the 1944-1977 County and City Data Books come from the Inter-University Consortium for Political and Social Research (ICPSR) files 7735 and 7736.  Members of the ICPSR can access the raw data files from the ICPSR website.