Freely accessible information and data about Surface PM2.5, Surface NO2, OM/OC Dataset, NOy Deposition, Inverse Visibility, Dry Deposition, AMF Code, and GBD-MAPS provided by Washington University in St. Louis.

IPUMS provides census and survey data from around the world integrated across time and space. 

The National Historical Geographic Information System (NHGIS) provides population, housing, agricultural, and economic data, along with GIS-compatible boundary files, for geographic units in the United States from 1790 to the present.

Policy Map provides data related to real estate markets, demographics, education, health, and jobs in maps, tables, and report.

The Census Bureau's mission is to serve as the leading source of quality data about the nation's people and economy.

The EarthExplorer user interface is an online search, discovery, and ordering tool developed by the United States Geological Survey (USGS). EarthExplorer supports the searching of satellite, aircraft, and other remote sensing data.

This would include residential, commercial, industrial and agricultural classes of property.

Copernicus is a European Union Programme aimed at developing European information services based on satellite Earth Observation and in situ (non-space) data. The information provided by the Copernicus services can be used by end users for a wide range of applications in a variety of areas.

Slightly over 129,000 households across the nation participated in the study.

The ASTER spectral library includes a comprehensive search tool which allows you to search the library database for your material. 

This server was developed by the Tennessee State & Federal GIS Users Group and is supported by the Tennessee Geographic Information Council (TNGIC) to distribute spatial data layers that are shared among Federal, State, and local GIS agencies and entities in Tennessee.

DIVA-GIS is a free computer program for mapping and geographic data analysis (a geographic information system (GIS). With DIVA-GIS you can make maps of the world, or of a very small area, using, for example, state boundaries, rivers, a satellite image, and the locations of sites where an animal species was observed. 

MapCruzin is an independent firm specializing in innovative Geographic Information System (GIS) projects, environmental and sociodemographic research, website development and hosting. MapCruzin's focus is on environmental justice and equality especially as it pertains to pollution, climate change, peak oil, energy, water, housing, food and technology.