Geographic Reference Files and Related Computer Programs from the 20th Census of Population and Housing

These files were developed and maintained to provide the basis for allocating collected data to their proper geographic area and to identify relationships between geographic areas, either hierarchically or over time. In addition, during the 1970s, the agency developed a major new computer-readable geographic data base for the United States and its possessions known as the Geographic Base File / Dual Independent Map Enco ding (GBF / DIME) system.

GBF / DIME files and the related software programs were used to assign census geographic codes to addresses (geocoding), and these data files were used for computer mapping of 1980 Census geography. This series contains files with political and / or census geographic referencing relating to the 1980 Census. The files are the 1980-1970 Tract Comparability File; Geographic Base File / Dual Independent Map Encoding (GBF / DIME); and Master Area Reference File 2.