Smaller collection; mainly Massachusetts, Rhode Island, and New England; some limited holdings on Southern maps. To get all maps, you have to filter separately by Genre > maps, Genre > maps (documents), or Format > cartographic.
Search "maps" in the Subject facet. A collaboration of the University of Utah, Brigham Young University, the University of Nevada, and other western libraries. Strengths in Utah, Nevada, and westward migrations.
No good way to search for maps only, since "Map" subject excludes many cartographic results. For specific map collections, see: https://www.library.wales/discover-learn/digital-exhibitions/maps.
Strengths in Chicago & the Midwest, American Indian history, and the U.S. West. Search functionality is somewhat confusing. Ask for help if you need it!