From a letter dated 4/20/1775, the day after the battles:
During the whole affair the Rebels attacked us in a very scattered, irregular manner, but with perseverance and resolution, nor did they ever dare to form into any regular body. Indeed they knew too well what was proper, to do so.
Whoever looks upon them as an irregular mob will find himself much mistaken. They have men amongst them who know very well what they are about, having been employed as Rangers against the Indians and Canadians; and this country, being much covered with wood, and hilly, is very advantageous for their method of fighting.
Nor are several of their men void of a spirit of enthusiasm, as we experienced yesterday, for many of them concealed themselves in houses and advanced within 10 yards to fire at me and other officers, though they were morally certain of being put to death themselves in an instant.
You may depend upon it that as the Rebels have now had time to prepare, they are determined to go through with it, nor will the insurrection turn out so despicable as it is perhaps imagined at home. For my part, I never believed, I confess, that they would have attacked the King‘s troops, or have had the perseverance I found in them yesterday.