The recently launched collection of about 100 digitized maps can be found in the Tennessee Virtual Archive (TeVA).
From the Map Collection Homepage:
These digitized maps appear in the JPEG2000 format, which means that you may view them in greater detail simply by clicking on a particular area of the image. We will continue to add maps to this digital online collection to bring more of them to a wider public.
TeVA also contains a collection of Civil War Maps.
TeVA is powered by OCLC’s CONTENTdm.
Source: Tennessee Secretary of State