Illinois Natural Resources Geospatial Data Clearinghouse
Access Illinois GIS data sets and documentation (metadata) for ArcIMS Interactive Map Services, USGS digital topographic maps, aerial photography, orthoimagery, orthophotography, geology, land use, natural resources, and infrastructure.
Illinois Department of Public Health, Data & Statistics
Link to several sources of public health statistics for the state of Illinois.
Coles County GIS and Coles County Regional Planning: GIS
From the Coles County Regional Planning & Development Commission. Also search the Coles County Tax Map Viewer: data may be viewed in an Internet browser, but cannot be downloaded.
U.S. Geological Survey
The National Map
A public collection of standardized nationwide datasets at a high level of resolution, including elevation, hydrology, transportation, administrative boundaries, land cover, imagery and the popular USGS topographic map series.
National Map Small-Scale Collection
Commonly used base data for the United States.
U.S. Census Bureau
U.S. Census Data
Access data about the United States, Puerto Rico and the Island Areas on such topics as people and population, race and ethnicity, families and living arrangements, health, education, business and economy, employment, housing, and income and poverty.
TIGER/Line Shapefiles Data
Cartographic boundary files for states, counties, and smaller census enumeration units, with additional base data including roads and streams. To access the data, select a year, then click Download and choose "Web interface."
TIGER/Line Shapefiles pre-joined with Demographic Data
A limited set of TIGER/Line Shapefiles are available pre-joined with data in geodatabase and shapefile format. (Also see TIGERweb to view spatial data online or stream to your mapping application.)
Historical Census Data (National Historical Geographic Information System - NHGIS)
Summary statistics and GIS boundary files for U.S. censuses and other nationwide surveys from 1790 through the present.
U.S. Centers for Disease Control and Prevention (CDC)
CDC WONDER (Wide-ranging Online Data for Epidemiologic Research)
An easy-to-use, menu-driven system that makes the information resources of the CDC available to public health professionals and the public at large. It provides access to a wide array of public health information.
U.S. Department of Health and Human Services
This information includes clinical care provider quality information, nationwide health service provider directories, databases of the latest medical and scientific knowledge, consumer product data, community health performance information, government spending data and much more. From CMS, CDC, FDA, NIH, and others.
U.S. Department of Agriculture
Census of Agriculture
The leading source of facts and figures about American agriculture. Conducted every five years, the Census provides a detailed picture of U.S. farms and ranches and the people who operate them.
Areas of specific cropland since 1997, from the USDA National Agricultural Statistics Service. Metadata for Cropscape are available here.
Downloadable agricultural statistics for every state and county in the U.S.
Soil Survey Geographic Database (SSURGO)
County level soil survey data.
Federal Highway Administration
Highways and bridges. Also contains links to many other federal GIS data sources.
Searches a comprehensive catalog of government data maintained by Data.gov and only returns geospatial data. GeoPlatform was developed by the member agencies of the Federal Geographic Data Committee (FGDC) through collaboration with partners and stakeholders.
The U.S. Government's open data at the federal, state, and local levels.
A volunteer-led resource that provides common GIS data layers for the entire world at three different scales. Natural Earth data has been cartographically generalized for small-scale mapping, meaning the data files are relatively small and easy to work with and are suitable for maps of larger regions (e.g. several states, a country, a continent or the entire world).
A crowdsourced alternative to commercial geobrowsers such as Google Maps, with data on roads, buildings and points of interest (POIs). All OSM data around the world is in the public domain and available for download (warning: large file sizes).