This site makes extensive use of the geographic feature names and locations as maintained by the U.S. Geological Survey (USGS) in the USGS Geographic Names Information System (GNIS), the official Federal database for domestic geographic feature names data as designated by the U.S. Board on Geographic Names.
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 census demographic estimates and 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: 2015/2020 Esri US Demographic Updates.