What is GIS?
A geographic information system (GIS) integrates hardware, software, and data for capturing, managing, analyzing and displaying all forms of geographically referenced information.
GIS allows us to view, understand, question, interpret, and visualize data in many ways that reveal relationships, patterns, and trends in the form of maps, globes, reports and charts.
A GIS helps you answer questions and solve problems by looking at your data in a way that is quickly understood and easily shared.
GIS technology can be integrated into any enterprise information system framework.
(esri.com)
Global Geographic Data Source
Environmental Data Explorer from the United Nations
Its online database holds more than 500 different variables, as national, subregional, regional and global statistics or as geospatial data sets (maps), covering themes like Freshwater, Population, Forests, Emissions, Climate, Disasters, Health and GDP.
ESRI Data & Maps
Hosted by Duke University
U.S. Geographic Data Resources
Bureau of Land Management (BLM) GIS Data
GeoSpatial Data Gateway from the USDA
Federal Geographic Data Committee
The FGDC coordinates the sharing of geographic data, maps, and online services through an online portal, GeoPlatform.gov, that searches metadata held within the NSDI Clearinghouse Network. The GeoPlatform portal is operated in support of the Geospatial Platform Initiative to provide “one-stop” access to all registered geographic information and related online access services within the United States.
Data.gov
Data.gov is the home of the US government’s open data.
You can find Federal, state and local data, tools, and resources to conduct research, build apps, design data visualizations, and more.
The Data.gov team works at the U.S. General Services Administration, but the site itself is open source, and we’d love your help making it even better.
National Atlas Data Downloads
Nearly all data available in the National Atlas Map Maker can be downloaded at no cost. National Atlas Data and Documentation are accessible from the table at this site.
GeoSpatial Data Gateway
The Geospatial Data Gateway (GDG) is the One Stop Source for environmental and natural resources data, at anytime, from anywhere, to anyone. The Gateway allows you to choose your area of interest, browse and select data from our catalog, customize the format, and have it downloaded or shipped on CD or DVD.
The National Map Viewer and Download Platform
Use The National Map Viewer and Download Platform to visualize, inspect, and download our most current topographic base map data and products for free. Managed by the USGS National Geospatial Program (NGP), The National Map Viewer provides access to all eight primary data themes of The National Map to include US Topo and historical topographic map products.
National Historical Geographic Information System
The National Historical Geographic Information System (NHGIS) provides, free of charge, aggregate census data and GIS-compatible boundary files for the United States from 1790 to present.
Alabama
Alabama County Shapefiles
AlabamaView is a consortium formed to promote research, education, and outreach of remote sensing and geographic information systems to Alabama citizenry. A major focus of AlabamaView is to provide centralized access to downloadable remotely sensed imagery and GIS layers.
Geospatial (Geographic Information Systems) Data
GIS data of Geographic Reference, "Aerial Imagery" Digital Data, DEMs, Soils, Hydrologic Data, Land Use and Land Cover, Geology and GeoPhysical Data can be reached in this website. Click the icon on the right for short list of FREE data viewers that you can download.
Geospatial Data for Alabama from the National Forest Service
Administrative Boundary, FS Ownership, Roads, water GIS data of Alabama
Alaska
Alaska Geospatial Data Clearinghouse
Alaska Spatial Data from the BLM
Welcome to the Bureau of Land Management's Spatial Data Management System website. The SDMS website provides access to on-line BLM-Alaska land record documents, reports and GIS data.
Arizona
Arkansas
California
Caltrans GIS Data Library
California Dept. of Transportation Data
Colorado
Connecticut
Delaware
Florida
Georgia
Georgia GIS Clearinghouse
Login required
Georgia Spatial Data Infrastructure
Login required
Hawaii
Idaho
Illinois
Iowa
Iowa Geospatial Data Clearinghouse
Login required
Iowa Natural Resources GIS Library
Iowa Geographic Map Server
Not necessarily data but really great maps and tools
Kentucky
Louisiana
Massachusetts
Michigan
Minnesota
Mississippi
Nebraska
New Hampshire
NH GRANIT
New Hampshire's Statewide Geographic Information System (GIS) Clearinghouse.
New York
North Carolina
North Dakota
Ohio
Oregon
Pennsylvania
South Carolina
South Dakota
Tennessee
Texas
Washington
Data Sources
American FactFinder
American FactFinder provides access to data about the United States, Puerto Rico and the Island Areas. The data in American FactFinder come from several censuses and surveys.
ReferenceUSA
Addresses, sales information, executives, for U.S. companies. Many search criteria and searches can be customized by company size, sales volume, geographic location, industry, etc.
*REQUIRES A VALID LIBRARY CARD*
DemographicsNow
Provides complete access to current and past U.S. Census data, with demographic maps and reports for all U.S. geographies and addresses, accurate market and site location analysis.
*REQUIRES A VALID LIBRARY CARD*
Environmental Data Explorer at the U.N.
The Environmental Data Explorer is the authoritative source for data sets used by UNEP and its partners in the Global Environment Outlook (GEO) report and other integrated environment assessments.
Census of Agriculture (USDA)
Conducted every five years, the Census provides a detailed picture of U.S. farms and ranches and the people who operate them.
Foreign Agriculture Service Data
The Foreign Agricultural Service (FAS) is responsible for collecting, analyzing, and disseminating information about global supply and demand, trade trends, and market opportunities.
Duke University Data Collections
Mostly free resources covering historic and current data topics for the U.S. and the World
USA.gov Data & Statistics
Provides access to the full range of official statistical information produced by the Federal Government without having to know in advance which Federal agency produces which particular statistic.
FAOSTAT
Food and Agriculture Organization of the United Nations offers large series data relating to food and hunger.
GeoHive Global Statistics
The main component is tabulated population statistics: current, historical, estimates, projections, cities, agglomerations, etc.