North Carolina Maps: http://www2.lib.unc.edu/dc/ncmaps/index.html. Sanborn Insurance Maps through 1922 are available free on this site. Click the Sanborn Maps tab.
Sanborn Maps North Carolina (http://sanborn.umi.com/), a product of ProQuest, is the most complete set of North Carolina Sanborn maps available online and includes maps after 1922. [...]