The city of Boston was girdled by rapidly increasing earthworks.  These were wholly defensive, to resist assault from the British garrison, and not, at first, as cover for a regular siege approach against the Island Post.  They soon became a direct agency to force the garrison to look to the sea alone for supplies or retreat.

Open war against Great Britain began with this environment of Boston.  The partially organized militia responded promptly to call.

The vivifying force of the struggle through Concord, Lexington, and West Cambridge (Arlington now), had so quickened the rapidly augmenting body of patriots, that they demanded offensive action and grew impatient for results.  Having dropped fear of British troops, as such, they held a strong purpose to achieve that complete deliverance which their earnest resistance foreshadowed.

Lexington and Concord were, therefore, the exponents of that daring which made the occupation and resistance of Breed’s Hill possible.  The fancied invincibility of British discipline went down before the rifles of farmers; but the quickening sentiment, which gave nerve to the arm, steadiness to the heart, and force to the blow, was one of those historic expressions of human will and faith, which, under deep sense of wrong incurred and rights imperilled, overmasters discipline, and has the method of an inspired madness.  The moral force of the energizing passion became overwhelming and supreme.  No troops in the world, under similar conditions, could have resisted the movement.

The opposing forces did not alike estimate the issue, or the relations of the parties in interest.  The troops sent forth to collect or destroy arms, rightfully in the hands of their countrymen, and not to engage an enemy, were under an involuntary restraint, which stripped them of real fitness to meet armed men, who were already on fire with the conviction that the representatives of national force were employed to destroy national life.

The ostensible theory of the Crown was to reconcile the Colonies.  The actual policy, and its physical demonstrations, repelled, and did not conciliate.  Military acts, easily done by the force in hand, were needlessly done.  Military acts which would be wise upon the basis of anticipated resistance were not done.

Threats and blows toward those not deemed capable of resistance were freely expended.  Operations of war, as against an organized and skilful enemy, were ignored.  But the legacies of English law and the inheritance of English liberty had vested in the Colonies.  Their eradication and their withdrawal were alike impossible.  The time had passed for compromise or limitation of their enjoyment.  The filial relation toward England was lost when it became that of a slave toward master, to be asserted by force.  This the Americans understood when they environed Boston.  This the British did not understand, until after the battle of Bunker Hill.  The British worked as against a mob of rebels.  The Americans made common cause, “liberty or death,” against usurpation and tyranny.