Wikipedia - entry with a comparatively good-size list of global, regional, and country-level resources; easy way to find geographic coordinates of populated places
https://freegisdata.rtwilson.com/#home - links to everything from arctic permafrost maps to gridded population data - simply scroll through the list or use the dropdown menus above to jump to a specific section of interest. See the FAQ for more information on the what, who, how and why of the list
University of Texas - lists of various geoportals
https://github.com/awesomedata/awesome-public-datasets - a comprehensive list of open data portals that includes spatial and non-spatial data. The list is organized by data subject area to facilitate browsing.
The Spatial Blog – free GIS sources as well as ArcGIS add-ins
GISGeography – a portal for various GIS datasets
Social Explorer – visualize and interact with data, create maps, charts, reports and downloads that help you reach your goals; explore hundreds of thousands of built-in data indicators related to demography, economy, health, politics, environment, crime and more; add your own data
Data.census.gov – platform to access data and digital content from the U.S. Census Bureau; download the TIGER/Line Shapefiles, which contain geographic entity codes (GEOIDs) that can be linked to the Census Bureau’s demographic data
Natural Earth – a public domain map dataset available at 1:10m, 1:50m, and 1:110 million scales, featuring tightly integrated vector and raster data; data themes are available in three levels of detail; for each scale, themes are listed on Cultural, Physical, and Raster category pages
data.gov – the federal government’s open data site with over 200,000 datasets from hundreds of data sources including federal agencies, states, counties, and cities
DIVA-GIS – free country-level spatial data for any country in the world: administrative boundaries, roads, railroads, altitude, land cover, population density; also: global climate data, species occurrence data, crop (genebank) collection data, near global 90 meter resolution elevation data, high resolution satellite images (LandSat) for nearly all of the world in the MrSid format that can be visualized in DIVA-GIS (in UTM projections)
Earth Explorer (USGS) - online search, discovery, and ordering tool developed by the United States Geological Survey; supports the searching of satellite, aircraft, and other remote sensing inventories through interactive and textual-based query capabilities
National Geospatial Program (USGS) – provides a foundation of digital geospatial data representing the topography, natural landscape, and manmade environment of the United States; data and derived products and services can be accessed through The National Map Data Download
NHGIS – provides free online access to summary statistics and GIS files for U.S. censuses and other nationwide surveys from 1790 through the present; account (free) is required
EarthWorks – maintained by Stanford University; discover and download world GIS data and maps
World Wildlife Fund – open access Conservation science datasets, incl. ecoregions, hydrosheds, river basins, etc.
GeoNetwork – open source database developed by FAO; free download of various GIS datasets
Euratlas – European maps and GIS data in vector format
Atlas of Historical County Boundaries - download GIS, KMZ, or PDF file formats of historical county boundaries for individual states in the United States of America; view and interact with animations of how county and territory boundaries have changed since the 1600's
Western Pennsylvania Regional Data Center – regional open-data portal, providing the infrastructure in support of the dissemination of raw data, data documentation, and managing information
Pennsylvania Spatial Data Access – Pennsylvania's official public access open geospatial data portal
Historic Pittsburgh - primary and secondary sources about the greater Pittsburgh region, including a wide range of publications, maps, manuscripts, visual images, and audio-video materials, that support personal and scholarly research
ArcGIS Hub - community engagement platform that organizes people, data, and tools; ArcGIS Hub is available at two license levels: Basic and Premium. ArcGIS Hub Basic is included with ArcGIS Online and delivers data sharing and site creation capabilities, while ArcGIS Hub Premium includes additional features and capabilities
OpenStreetMap (OSM) – open source; built by a community of mappers that contribute and maintain data about multiple features all over the world
MapCruzin - GIS aggregation site including wide range of data for various areas of the world. Some datasets appear to be of low quality, but others are very good
OpenTopography - portal to high spatial resolution topographic data and tools. In particular, it houses LiDAR Data; 300 high resolution datasets, most of which are point clouds; some are just available in raster format; most available data is in the United States; some data is also available in Europe, Asia and Australia
GeoNetwork - portal of free GIS data from the United Nations
https://globalmaps.github.io/ - no longer exists; however, rich GIS data available on their archived GitHub
Geolode - collaborative catalog of geospatial open data websites around the world, searchable and browsable by location, topic, and other tags, so that searchers can quickly focus on the most relevant websites for their geodata needs
USDA National Resources Conservation Service Geospatial Data Gateway - links to the USDA National Resources Conservation Service Geospatial Data Gateway; provides elevation data sets for selected states and counties, as well as other types of geospatial data such as census coverage, climate data, geology, and others
USGS Long Term Archive Products - view satellite images and data, aerial photography, elevation and land cover datasets, and digitized maps from a variety of sensors; the archive contains images from 1937 to present, which you can also order or download at no charge
National Flood Hazard Layer GIS Status - you can access the National Flood Hazard Layer Inventory Table, which allows you to download the most recent GIS layers of Flood Insurance Rate Maps for the United States National Flood Insurance Program
United States Fish and Wildlife Geospatial Services - links to the United States Fish and Wildlife Service Geospatial catalog; access geospatial data and maps related to the mission of the Fish and Wildlife service
DataBasin - provides free access to thousands of scientifically grounded, biological, physical, and socio-economic GIS datasets, although you will need to create a free account to download data
OpenDataSoft Data Network - excellent resource for users looking for geospatial data. The workflow used to develop the data portal list is well documented, the list is impressively comprehensive with 2900+ portals listed, and the portal links are clearly organized by geographic area
US City Open Data Census - provides links to open local government datasets, but also ranks cities based on their data sharing policies
Global Open Data Index - ranks countries based on their level of data openness and provides links to specific datasets (both spatial and non-spatial)
OpenDataMonitor - EU funded website that ranks the data openness of European countries and makes it easy to find national, provincial, and city level geoportals by browsing by country of interest
The Atlas of Canada - provides a selection of interactive and historical maps and geographical data available for reference or downloading
Topographic Data of Canada CanVec Series - contains more than 60 topographic features classes organized into 8 themes: Transport Features, Administrative Features, Hydro Features, Land Features, Manmade Features, Elevation Features, Resource Management Features and Toponymic Features
Harvard University China Historical GIS - free database of placenames and historical administrative units for the Chinese Dynasties; provides a base GIS platform for researchers to use in spatial analysis or to visualize the historical divisions of China as digital maps
Harvard University Japan Historical GIS - Harvard also offers historical boundary data from the 1500s to 1800s for Japan for download
HGIS de las Indias - features thousands of boundary files covering colonial Spanish America from 1701 – 1808
The Historical GIS for the Netherlands – a collection of shapefiles of the Netherlands for the years between 1812-1997
Historical GIS Germany - datasets and interactive maps on German spatial history since 1648
Data Basin - open access database; thousands of scientifically-grounded, biological, physical, and socio-economic datasets
Global River Database – free ESRI Shapefiles are provided as ZIP files per continent
The US Department of HUD-eGIS Storefront - provides a one-stop shop where users can search for and discover HUD's geospatial datasets, web-based mapping tools, and application programming interfaces (APIs)
http://library.thinkquest.org/C006628/download.html - shapefiles of the political world, 2000BCE-1994CE
CShapes - dataset that provides historical shapefiles of state boundaries and capitals in the post-World War II period
Pleiades Project - collects historical geographical information about places most predominately for the Greek and Roman world, and is expanding into Ancient Near Eastern, Byzantine, Celtic, and Early Medieval geography. The data can be downloaded in CSV, JSON, and KML formats
Jeremy Atack, Vanderbilt University - historical transportation shapefiles that cover the spread of different modes of transportation in the Lower 48 states from this nation’s founding through (approximately) 1911
