Out of curiosity, is there a reason you've chosen to focus on "dark" events in the path? Is it because of the shadow metaphor? I'm sure there are plenty of good things that happened in the path too.
The Trail of Tears and Sullivan's island leapt out at me the very first time I saw a map of the shadow path and I have for years thought that an honest painful day of atonement around the world would be healing and humbling and a good antidote to romanticized militarism. Only Germany has come close to real atonement. Most of the rest of the world is way overdue. So I thought it would be a valuable addition to a day that bonds a nation with many of the best activities for creating harmony - dancing, cheering, working and eating together rounded out with crying together and promising never again together. Many of my thoughts are in the proposal which is way long as the event is complicated. But I have run a camp at Burning Man I have been to the Virgin of Guadalupe Festivities, and past a critical point adding events and complexity really does create an unstoppable frenzy that is more and more likely to succeed and pretty soon you can't keep people away.