The geographic data for the physical, cultureal and historic features is based on the Geographic Names Information System (GNIS). The GNIS is maintained by the US Geological Survey (USGS) and is the official Federal database for domestic geographic feature names and locative information.
The Guide to State and Local Census Geography was a source document for the basic data, history and much of the geographical areas information found on the home page of this gazetteer.
The annual census demographic estimates and 5-year forecasts are based upon data produced by Esri Demographics. Their estimates and forecasts use the latest US Census Bureau annual American Community Survey (ACS) as a starting point. They then combine additional data from multiple sources including residential postal deliverly counts from the USPS, a time series of county-to-county migration patterns from the IRS, building permits, housing starts and local data sources that tested well against Census 2010. For more detailed information: Methodology Statement: 2016/2021 Esri US Demographic Updates.
The primairy data source for our school profile data is the National Center for Education Statistics (NCES) at the US Department of Education.