One of the most compelling combinations of a history timeline and a map I have ever seen!
In a nutshell, the map shows the loss of territory by native Americans from 1776 until present.
This should be shown and assigned as homework in every American history class.
Some people who merit a special shout-out for this work:
The Invasion of America is a project of eHistory.org.
Project director: Claudio Saunt, Russell Professor of History at the University of Georgia
Technical director: Sergio Bernardes, Center for Geospatial Research
Special thanks to David Holcomb and Daniel Reeves at ITOS for implementing the map on ArcGIS Server.