The History Project is an experiment in representing historical information in an OSM style database, suitable for standalone display or for use as an overlay on core OSM data. The current plan is to host one or more "playpens" on OSM US servers.
Currently Proposed Projects
It would be great if the boundaries of countries at different times in the past were included. Being able to move a bar at the bottom of the screen to see the boundaries of various countries change would be of tremendous value.
The American Civil War
Mapping significant events, site, etc. Charting the course of campaigns and battles Showing the movements and positions of units
Details and locations of historic auto racing tracks in the US and Canada.