Geographer Chauncy Harris often argued that Chicago in the first half of the 20th century was the most studied city in the world. This claim is unprovable, but there were certainly an enormous number of scholarly studies of Chicago between the 1920s and the middle of the 20th century. Many of these included maps.
This Web site provides links to a few of the social science maps of Chicago that are held as separate pieces by the University of Chicago Library's Map Collection. Included here are several products of the "Chicago School of Sociology" including the Social Base Map of Chicago; a group of anonymous neighborhood maps; several maps of land use or land value by (or connected with) Homer Hoyt; and maps from books by Frederic Thayer on gangs, Walter Reckless on "vice," and Clifford Shaw on crime. These maps were created during the 1920s and the 1930s, at more or less the same time as another Chicago School product, the Social Science Research Committee census maps. It is arguable that, at the moment of their creation, the Chicago School maps made up the most wide-ranging cartographic portrait of an urban area that had ever been compiled.
Also included are several of geographer Harold Mayer's railroad maps; anthropologist Sol Tax's manuscript cartographic representation of blockbusting in the Hyde Park area; and other maps as well.