Datasets

Centre for the Study of Civil War: Geographical and Resource Datasets
http://www.prio.no/CSCW/Datasets/Geographical-and-Resource/

Data on geographical aspects that influence the risk and nature of civil wars.

Geospatial Data Gateway, Natural Resources Conservation Service, US Department of Agriculture
http://datagateway.nrcs.usda.gov

Download natural resources datasets from states and counties.

Geospatial One Stop, geodata.gov
http://gos2.geodata.gov/wps/portal/gos/

Find federal, state and local geographic datasets at this site.

Global Biodiversity Information Facility http://data.gbif.org/datasets/

A portal to millions of data records from all over the world on biodiversity, including benthic and marine organisms.

National Hydrography Dataset  http://nhd.usgs.gov/

"The NHD is a comprehensive set of digital spatial data representing the surface water of the United States using common features such as lakes, ponds, streams, rivers, canals, and oceans. These data are designed to be used in general mapping and in the analysis of surface-water systems using geographic information systems (GIS)" (quoted from website).

National Park Service Data Clearinghouse
http://www.nps.gov/gis/data_info/

Geographic datasets for national parks, forests, historic sites, etc.

Off the Map blog: Dataset of the Day
http://blog.fortiusone.com/category/dataset-of-the-day/

Blogger is Sean Gorman, owner of FortiusOne

SAGE Maps, Datas, Models http://www.sage.wisc.edu/mapsdatamodels.html

Various land use datasets from the Center for Sustainability and the Global Environment (SAGE) at the University of Wisconsin-Madison.