Sanborn Fire Maps and Other Historical Maps?

[Richard A Fuhrman 0]

I'm new to TNG (V. 10) and am trying Template 9.

 

I would like to have a "Historical Maps" category added to the left panel.  As some might know, for example, Sanborn Map Co. (https://en.wikipedia.org/wiki/Sanborn_Maps) published wonderful "fire maps" for 12,000 American communities over the course of a century. These can be downloaded as .pdf's at most major public libraries. They are very neat to attach to records: They show the "downtowns" the way that they used to be. It would be great to organize them into a single category. Just a thought.