History: July 2012 Archives
GIS Lounge: Over 120 Years of Mapping History Online
"The USGS Historical Topographic Map Collection currently makes over 98,000 maps dating as far back as 1884 available to the public. The maps are available in GeoPDF format and can be downloaded for free from the USGS store."
GIS Lounge: Where to Look for Historical Maps
Before you make the digital map, you have to start with a hardcopy or scan. Here's a long list of sources for maps and aerial views.