The National Oceanic and Atmospheric Administration has historical aeronautical and nautical charts available at this site. You can find charts by either typing in a place name or clicking on a location on a map.
Similar to the Kalamazoo and Portage GIS services, this mapping website allows you to view tax maps, a countywide generalized zoning map, aerial imagery from 2009-2013, a water table map, a map of areas that require a soil erosion permit and many other themes.
Search and browse thousands of large-scale maps of American towns and cities, searchable by address and GPS coordinates. Tools are available that layer maps from different years on top of each other and over modern street, satellite, and hybrid layers via a Google™ map interface
Old Maps Online serves as a gateway to a number of large collections of historical maps that have been digitized. A map on the screen serves as the interface with search results appearing in the right hand column. You can also search by place and limit by time period.
The Map and Geospatial Information Round Table (MAGIRT) of the American Library Association provides this list of map scanning projects. You can browse or search for projects covering areas of interest. It is notable because entries include basic technical information about the projects.