If you love historical maps, tops and the like then you’ll really appreciate the USGS’ data holdings. The U.S. Geological Survey (USGS) has publicly released more than 161,000 digitally scanned historical maps spanning in excess of 130 years and covering the conterminous lower 48 states. The Historical Topographic Map Collection can now offer, for free download, digital versions of the USGS legacy topographic map series which includes all scales and all editions originally published for the entire continental U.S.
The maps are offered to the public at no cost in GeoPDF format or as a printed copy for $15 – See the Historical Topographic Map Collection
Note: For historical map prints See also this fine collection from Amerisurv