Since its early beginnings in the mid-20th century, Geographic Information Systems (GIS) has revolutionized the nature of cartography, allowing the world's spatial features to be digitally stored as geospatial data, creating pathways for born-digital cartographic products and spatial analysis. GIS is a computerized data system that is capable of capturing, storing, managing, analyzing, and visualizing spatially referenced information. Geospatial data encompasses a wide range of spatial features and types of analysis, wielding the potential for simple exploration of spatial patterns to critical decision-making. For example, examining bighorn sheep sighting locations with temperature isotherms and elevation contours may give some insight into the climatic nature of that species habitat. Similarly, mapped demographic characteristics such as age, race, gender, and economic status can help inform policy analysis and government decision-making. The Geography & Map Division has been using and collecting geospatial data and software since the early 1990s and has celebrated GIS Day annually since its founding in 1999. For more information on available digital geospatial collections, see Geospatial Data and Georeferenced Maps. For more about collection material which documents the creation and evolution of GIS and remote sensing, learn about the History of Computer Cartography and Geographic Information Sciences Archive For further information on these materials, please contact us via Ask a Librarian.

The Geography & Map Division also uses authoritative federal spatial data to make maps for Congress, alongside the Congressional Research Service (CRS), through the Congressional Cartography Program. Federal data is available through GeoPlatform, which was developed by the Federal Geographic Data Committee (FGDC) and recognized as the federal access point for geospatial data by the Geospatial Data Act of 2018. The Division also uses geospatial technology to publish public web maps which visualize and create entry points into Library of Congress collection material.