This data release comprises four datasets that represent Phosphorus concentration in the A and C horizon of soils within the conterminous United States. The source dataset is a slight modification of the data published in the report "Geochemical and mineralogical data for soils of the conterminous United States", http://pubs.usgs.gov/ds/801/. Data were interpolated for use in models associated with the National Water Quality Assessment program of the USGS. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using Inverse Distance Weight (IDW) algorithm. Two datasets are of Phosphorus in soil A horizon and C horizon, interpolated using IDW, and then aggregated to Geologic Mapping Units (GMUs).