The U.S. Geological Survey (USGS) has released another 13,688 historical topographic maps covering California from its Historical Topographic Map Collection. Arizona is scheduled to be completed this Fall. According to a recent announcement:
Nearly 124,000 high resolution scans of the more than 200,000 historical USGS topographic maps, some dating as far back as 1884, are now available online. The Historical Topographic Map Collection includes published U.S. maps of all scales and editions, and are offered as a georeferenced digital download or as a scanned print from the USGS Store.
Historical maps are offered to the public at no cost in GeoPDF format or as a printed copy for $15 plus a $5 handling charge from the USGS Store and can be used in conjunction with the new USGS digital topographic map, the US Topo. Check the website for continuous updates: http://nationalmap.gov/historical
The project is part of the USGS National Geospatial Program (NGP).