Google Earth has added 16 historic maps from the David Rumsey Map Collection. Once you’ve downloaded the program, click on “Featured Content.” “Rumsey Historical Maps” is currently the first item listed. Click on the little circle to the left of the map name you’re interested in - and then fly over the world as it was mapped a couple centuries ago!

Use the sliders and directional wheel on the page to compare old and new maps - and zoom in and out - and around and around. What fun! This is a wonderful and unique melding of historic mapping with new technologies.