Data > Sources by Subject

One way to narrow down your search is to look for topical websites and data portals. The General Data Sources and Government Data Sources are most helpful for searching all kinds of data at the global scale. If you already know the specific type of data you want, check out the Data by Subject to see some of the categories we’ve curated. Keep in mind that there are many more resources out there, so if you can’t find what you are looking for here, try searching the web!

General Data Sources

Open Data

Collaborative catalog of geospatial open data websites around the world, searchable and browseable by location, topic, and other tags.

Esri Data

Requires Enterprise login with UMass ID

ArcGIS Hub
Data-sharing platform for organizations around the world.

ArcGIS Living Atlas of the World
Browse through a global collection of maps, apps, and data layers published by other Esri users, and incorporate them into your own maps.

Esri Maps and Data
Search for imagery, basemaps, elevation, demographic data, and other layers curated by the Esri team.

Government Data Sources

Many state, federal, and national governments provide access to GIS data, including remotely sensed satellite imagery, orthophotos, topographic maps, natural resource vector layers, and more.

European Union

European Union’s Earth Observation Programme, providing free and open access to an ever-growing collection of global Sentinel satellite imagery and derived products. Includes data from the European Space Agency and the European Organisation for the Exploitation of Meteorological Satellites.

U.S. Department of Agriculture

Geospatial Data Gateway
Map library of over 100 high resolution vector and raster layers in the Geospatial Data Warehouse. It is the main source for environmental and natural resources data, at any time, from anywhere, to anyone. It allows you to choose your area of interest, browse and select data, customize the format, then review and download.

Map viewer for the Cropland Data Layer (CDL), a georeferenced, crop-specific land cover data layer created annually for the continental United States using moderate resolution satellite imagery and extensive agricultural ground truth. All historical CDL products are available for use and free for download through CropScape.

U.S. Geological Survey

Earth Explorer
Main data portal for searching, ordering, and downloading geospatial data from the USGS. Includes many free datasets from across the entire globe, including terrain data, Landsat imagery, and declassified CORONA spy-satellite imagery.

Map Locator
Map viewer tool for quickly identifying USGS maps covering your area of interest. Easy to download or purchase print copies.

The National Map
Data download application and web map services for “Topographic Information for the Nation,” including topographic maps and GIS data for elevation, hydrography, watersheds, geographic names, orthoimagery, governmental units/boundaries, transportation, and land cover.

National Land Cover Database
Cooperation with the Multi-Resolution Land Characteristics Consortium (MRLC), a partnership of Federal agencies working together to produce current, nationally consistent, land cover products for all 50 states and Puerto Rico.

Map viewer tool for downloading georeferenced historical USGS topographic maps from 1884–2006.

Other U.S. Sources

EPA Environmental Dataset Gateway
U.S. Environmental Protection Agency’s official open data catalog.
Data portal developed by the member agencies of the Federal Geographic Data Committee (FGDC). Download datasets and layers, access map services, and join data communities.

NASA Earth Science Data
National Aeronautics and Space Administration’s portal for downloading global-scale remote sensing data.

NOAA Maps and Geospatial Products
National Oceanic and Atmospheric Administration’s portal for viewing maps, story maps, and map services.

Data by Subject

Addresses, Geocoding

User-contributed list of addresses from across the globe.

User-contributed gazetteer of ancient places. Linked Open Data platform. 

Who’s On First
Global gazetteer of contemporary places with unique identifiers. Open data.

World Historical Gazetteer
In-development gazetteer of historical places. Linked Open Data platform.

Boundaries, Features

Database of Global Administrative Areas (GADM)
Maps and geospatial data – including political boundaries – for countries around the globe.

Natural Earth
Public domain vector and raster datasets available at 1:10m, 1:50m, and 1:110 million scales.

OpenStreetMap Data Downloader
Geofabrik’s free server for downloading data from the OpenStreetMap project.

Project Linework
By Daniel Huffman. Artistic country and U.S. state boundaries for making creative maps.


Electoral precinct data for each state, collected, cleaned, and validated by volunteers. Validated shapefiles are available for most states.


See the section on the U.S. Geological Survey for more links.

Massachusetts Geological Survey – Maps, Data, Pubs
List of maps, data, and publications curated by the MGS, housed in UMass Geosciences.

Historical Maps


David Rumsey Historical Map Collection
Digital collection of many of the physical maps in the David Rumsey Map Center at the Stanford University Library. Maps span the 16th through 21st century and cover the entire globe. Maps are downloadable and can be georeferenced using an online tool.

Digital Sanborn Maps (1867-1970)
Available on campus to all, or off-campus with a UMass ID. The Sanborn Fire Insurance Maps are large-scale town plans of streets and town blocks, originally created to help in insurance assessment. Browse and download any of the digitized (non-georeferenced) plans from the New England states. 

Leventhal Map & Education Center Digital Collections
Digital Collection of maps in Boston Public Library’s Leventhal Center. Search and download maps by collection or using search terms. Many georeferenced maps are available for download, or  can be georeferenced using an online tool. 

Leventhal Map & Education Center Atlascope
Tool for exploring georeferenced historical atlases of Boston. To work with the atlases in a GIS platform, see the tutorial Bring BPL Atlas Tiles into QGIS.

Perry-Castañeda Library Map Collection
Extensive collection of digitized maps from the University of Texas at Austin Libraries, browseable by region or topic. Includes both modern and historical maps.

UConn Library Historical Map Collection
Digital collection of historical maps from the UConn Library Map and Geographic Information Center (MAGIC), browseable by region. Particularly strong in maps from Connecticut and New England.

UMass Library Special Collections and University Archives
Selection of scanned historical maps from the UMass Amherst Libraries’ map collection.

UNH Library Historic USGS Maps of New England and New York
Digitized USGS quadrangles. Browse by quad name or township.


Boston University Libraries Maps, Atlases, Directories
List of resources for historical and modern maps of Boston. 

Digital Commonwealth – Massachusetts Archives Town Plans (1794)
Digitized plans of the towns in Massachusetts and southern Maine from 1794, searchable by map view or browse by place. Maps are viewable online but not downloadable. You can also access this map series on microform at the W.E.B. DuBois Library. Search the Libraries’ catalog for “Maps and plans, 1794 series,” or view the catalog record

Digital Commonwealth – Massachusetts Archives Town Plans (1830)
Digitized plans of the towns in Massachusetts from 1830, searchable by map view or browse by place. Maps are viewable online but not downloadable. You can also access this map series series on microform at the W.E.B. DuBois Library. Search the Libraries’ catalog for “Maps and plans. Series 2, Towns, 1830,” or view the catalog record.

Massachusetts Historical Society Online Massachusetts Maps
Digital collection of about 100 historical maps of Massachusetts and Boston, dating primarily to the 17th-18th centuries. Search by map view or browse by township.

State Library of Massachusetts Real Estate Atlases
Digital collection of MA real estate atlases dating from the late 19th and early 20th centuries. Atlases are downloadable as single PDFs (see the State Library’s Digital Repository) or viewed and downloaded as individual images (see the State Library’s Flikr Site).

Historical Photos

Online map platform for searching over 90,000 historical photos from the U.S. Farm Security Administration and Office of War Information (1935-1945).


Global / National

Source for census and survey data from across the globe, both historical and current.

National Historical Geographic Information System (NHGIS)
IPUMS resource for summary tables and times series of U.S. Census data from 1790 to today. Includes GIS boundary files.

Esri Demographics
Requires Enterprise login with UMass ID
. Global demographic data, including forecasts to 2024 of U.S. demographics.

U.S. Census Bureau

Census Data
Main portal for searching for U.S. Census Bureau data.

Geography Program
Collection of downloadable mapping files put together by the Geography Program of the U.S. Census Bureau, including TIGER/Line Shapefiles, TIGER/Line Geodatabases, and boundary files.

Public Health

Humanitarian Data Exchange (HDX)
Open data exchange managed by OCHA’s Centre for Humanitarian Data.

IHME Global Health Data Exchange (GHDx)
Collection of public health data from the Institute for Health Metrics and Evaluation.

WHO Global Health Observatory Data Repository
World Health Organization’s portal for health data for over 190 countries.

Remote Sensing

See the sections under Government Sources for more links.

Google Earth Engine
Provides access to global satellite imagery and geospatial datasets with built-in analytical capabilities, including an API and interactive timelapse. Researchers must apply to request access, and imagery can only be used for “development, research, or educational purposes.”

Planet Education and Research Program
Global satellite imagery acquired daily. Students, faculty members, and researchers may apply to gain limited, non-commercial access to Planetscope Imagery and Rapid Eye Archive.