Army Map Service Topographic Map Series (Perry-Castañeda Library, U. of Texas, Austin) Maps of other countries from the 1930s to the 1970s.
Geologic Atlas of the US (Texas A&M University) Maps of the US from 1894-1945.
Historic Pittsburgh Maps Collection Digital maps in Pitt's Historic Pittsburgh collection.
The National Map: Historical Topographic Map Collection (USGS) Topographic maps from the last 125 years.
United States Historical Topographic Maps (Perry-Castañeda Library, U. of Texas, Austin) Pre-1945 maps.
In addition to current maps for Pennsylvania, we retain older editions of USGS topographic maps as well. These can be found in the Topographic Maps section of the Hillman library map collection, shelved in the Pennsylvania drawers by quadrangle name.
The Geologic Atlas of the United States, published by the USGS (1894-1945), contains topographic and geologic maps for 227 quadrangles. We have many of these folios--especially for Pennsylvania--in our collection.
You may use PittCat+ to search for specific folios. These folios are shelved in storage. Anyone can ask for specific folios to be transferred to the Archives Reading Room for viewing. (The Archives Service Center is located in the Point Breeze neighborhood of Pittsburgh.) Also, anyone can ask for specific folios be transferred to Microforms in Hillman Library.
The entire Geologic Atlas of the United States is also available on the web from Texas A&M University.