Thanks for posting.
What is interesting is that the first shots of the war were actually 5 months earlier in New Castle , NH where the colonials raided the British Fort William & Mary to steal the munitions. A British soldier was killed in the raid.
http://en.wikipedia.org/wiki/Fort_William_and_Mary
The fort is now known as Fort Constitution.
Things were getting pretty belligerent before the 19th of April.
You had the Powderhouse Alarm in Somerville. You had the Salem Alarm in, well, Salem (or was it near Danvers?). You had the Gaspee Affair. You had the Fort William and Mary Alarm (as you mentioned).
To say nothing of the Boston Massacre and the Tea Party.
Lots of animosity building up to this fateful day in 1775.