View in Google Earth
Forgive me if this has been done already. I found a bunch of shapefiles for historical political boundaries on Cartotalk.com and exported them all to KML with TimeSpans.
I can not vouch for the accuracy of the boundaries or lack thereof in terms of place and time, but I think it looks interesting and would like some feedback. There seem to me to be several historical boundaries unaccounted for in this data set.
I used Google's default yellow lines so it probably looks best with many of GE's default layers off. After I showed it to somebody they suggested I use a colored fill for some of them so I tried it on one as you can see in the animated gif above. Thought about adding clickable placemarks for perhaps relevant wikipedia articles or something, but have not yet attempted that.
I like the idea of combining geography and history. A few ideas that interested me during this export:
Viewing various historical data with the Google Earth API and time slider such as:
changes in assessor/county/tax parcel data and geography
changes in municipal, state, and federal land planning and zoning
changes in land and housing values over time and space to inspect patterns on larger and smaller scales
changes in migration patterns
incident tracking over time
view-based refresh of historical imagery in cooperation with the time slider