These data, intended for use in conjunction with JUVENILE DELINQUENCY AND ADULT CRIME, 1948-1977 [RACINE, WISCONSIN]: THREE BIRTH COHORTS (ICPSR 8163), are organized into two different types: Block data and Home data. Part 1, Block Data, contains the characteristics of each block in Racine for the years 1950, 1960, and 1970 as selected from the United States Census of Housing for each of these years. The data are presented for whole blocks for each year and for blocks agglomerated into equal spaces so that comparison may be made between the 1950, 1960, and 1970 data. In addition, land use and target density (gas stations, grocery and liquor stores, restaurants, and taverns) measures are included. The data were obtained from land use maps and city directories. These block data have been aggregated into census tracts, police grid areas, natural areas, and neighborhoods for the purpose of describing the spatial units of each in comparable fashion for 1950, 1960, and 1970. The information contained within the Block Data file is intended to be used to merge ecological data with any of the files described in the ICPSR 8163 codebook. The Home datasets (Parts 2-6) contain selected variables from the Block Data file merged with the Cohort Police Contact data or the Cohort Interview data from ICPSR 8163. The Home datasets represent the merged files used by the principal investigators for their analysis and are included here only as examples of how the files from ICPSR 8163 may be merged with the Block data.