Yesterday morning I shared a collection of more than 100,000 historic maps for classroom use. In that post I mentioned using those maps to create digital overlays on current maps. Google Earth provides a couple of ways to do that. Felt.com is another digital mapping tool that can be used for the same purpose. 

In the following videos I demonstrate how to create historic map overlays for comparison purposes. 

Video – How to Create Historic Map Overlays on Felt.com

There are a couple of ways to overlay historical maps on current maps in Google Earth. The first is to simply use the Rumsey Historical Maps collection layer in Google Earth. That method is demonstrated here. The other method is to find a historic map, download it, then use it as an image overlay in Google Earth. That method is demonstrated here.