Los Angeles Public Library
The Los Angeles Public Library's (LAPL) online map collection mainly focuses on Los Angeles County and the West. Images contain descriptive metadata and may be downloaded.
Library of Congress
The Library of Congress (LC) holds one of the world's largest cartographic collections. The online collection features maps, panoramic views, pictorial maps of various cities and regions throughout the world. Materials may be downloaded and reused for research purposes. Citation styles are also provided.
Calisphere
Calisphere provides access to digital collections from institutions all over California. Calisphere contains all formats of digital materials, including papers, photographs, and maps. To find maps across all institutions, use the search query:
[City or County] AND map
You can then filter results by decade, institution, or collection.
Digital Public Library of America
The Digital Public Library of America (DPLA) provides access to digital collections from institutions all over the country. DPLA contains all formats of digital content. To find maps, enter "map" in search bar. You can filter by subject, location, and institution.
New York Public Library Digital Collections
The New York Public Library (NYPL) Digital Collections includes all format of materials, including photographs, postcards, illustrations, and maps. Geographic coverage for the map collection tend to focus on New York and surrounding areas, but some international maps and maps of western states are also available.
David Rumsey Map Collection
The David Rumsey Map Collection includes a large number of maps, charts, and views from all over the world. The Rumsey site holds a large number of maps of California and the West. Images may also be downloaded and used in research projects.
USGS TopoView
The United States Geological Survey (USGS) has made most of its 7.5-minute and 15-minute topographic collections available online through the TopoView site. Images are georeferenced and can be downloaded as regular image files or as geotiff files. The site supports spatial inquiry and maps can be found by searching locations.