To so occupy Charlestown, in advance, as to prevent a successful British
landing, required the use of the nearest available position that would
make the light artillery of the Americans effective. To occupy Bunker
Hill, alone, would leave to the British the cover of Breed's Hill, under
which to gain effective fire and a good base for approach, as well as
Charlestown for quarters, without prejudice to themselves.
When, therefore, Breed's Hill was fortified as an advanced position, it
was done with the assurance that reinforcements would soon occupy the
retired summit, and the course adopted was the best to prevent an
effective British lodgment. The previous reluctance of the garrison to
make any effective demonstration against the thin lines of environment
strengthened the belief of the Americans that a well-selected hold upon
Charlestown Heights would securely tighten the grasp upon the city
itself.