One huge aspect to events of "historical significance" is propaganda. Notice how many events of the utmost significance go virtually unnoticed, while often relatively minor events gain an undue amount of attention. This is not by accident; it is done because the propaganda serves a larger purpose.
The events in recent times, in Boston, have reminded me of just how people think during times like these. Its an interesting window into the way people are conditioned by propaganda and by injecting a fake narrative into historical events, to control people's emotions and their response. If you do the propaganda correctly, you can get people to do just about anything, so the payoff for pulling it off is huge compared to the cost. That's why it keeps happening and why it works in the best interest of the state and many of the corporations attached to the activities of the state (i.e. "crony capitalism", not to be confused with free market capitalism and a competitive marketplace).