U.S. Bureau of the Census, 1980. Master Area Reference File for 1980 Census. The point representing a tract can be anywhere within the tract. Some of the larger tracts were split. U.S. Geological Survey, Water Resources Div.
Point features present.
1.1 Documentation added. In general, each point represented the centroid of a census tract, although some tracts were split. The 1980 population was given for each point, along with latitude and longitude. The point coverage and its point attribute table were generated from these files, and the projection was changed to the standard Albers equal-area projection for the conterminous United States. The original processing for this coverage took place in 1986, and documentation records are incomplete.