This data set represents U.S. Geological Survey (USGS) historical Land Use and Land Cover (LULC) from the 1970's that has been refined with 1990 population density at the block group level to indicate new residential development representative of the 1990's. Any area having a population density of at least 1,000 people per square mile had been re-classified as "urban" land in this data set.
Additional publication details
USGS Unnumbered Series
1970's Land use data refined with 1990 population data to indicate new residential development for the conterminous United States