UW GIS Certificate Program Graduate Greg Grube produced these reports in conjunction with APL. Users will note a shift in geographic scale between 1980 partial block groups estimates and subsequent 1990 block level estimates. The sources of these estimates and the map production methods are described briefly here: WI Housing Density Report
1940 - 1980 Housing Density:
US Census Partial Block Group Data Hammer, R. B. S. I. Stewart, R. Winkler, V. C. Radeloff,and P. R. Voss. 2004. Characterizing spatial and temporal residential density patterns across the U.S. Midwest, 1940-1990. Landscape and Urban Planning 69: 183-199.
1990 - 2010 Housing Density:
US Census Bureau, Census block housing unit counts.