Northern theater · 1775
Boston Campaign
From Lexington and Concord through Bunker Hill and Dorchester Heights, the Boston Campaign transformed local resistance into an organized continental war and ended with the British evacuation of the city.
Operational geography
Campaign Movement Map
A proportional campaign overview using each battle record’s modern reference coordinate. It explains operational movement; it is not a surveyed reconstruction of 1776 unit positions.
- Battles of Lexington and ConcordAmerican strategic victory
- Battle of Bunker HillBritish tactical victory
- Dorchester Heights and the Evacuation of BostonAmerican strategic victory
Campaign sequence
Where This Battle Fits in Its Campaign
Campaign Engagements
April 19, 1775
Battles of Lexington and Concord
American strategic victory
June 17, 1775
Battle of Bunker Hill
British tactical victory
March 4, 1776
Dorchester Heights and the Evacuation of Boston
American strategic victory
From political crisis to armed mobilization
The Boston Campaign began not with a declaration of war but with an attempt to seize military stores. Lexington and Concord converted that mission into a regional uprising. Militia companies converged around Boston, and a political crisis became a siege. The campaign’s first analytical question is therefore mobilization: how quickly could each side generate usable military power after the first shots? British regulars possessed training and a fortified urban base; the provincial side possessed depth in local militia networks and control of much of the surrounding countryside.
Evidence basis: U.S. Army CMH — Revolutionary War Army History Trails
Why Boston could be contained but not immediately taken
The British garrison depended on the harbor and Royal Navy while American forces held much of the landward perimeter. That produced an unusual balance. The provincials could make movement outside the city dangerous but lacked the heavy artillery and organization needed for a direct reduction of Boston. The campaign became a laboratory for building an army while already in contact with the enemy.
Evidence basis: U.S. Army CMH — Revolutionary War Army History Trails
Bunker Hill tested the price of taking prepared ground
The June battle proved Britain could storm American fieldworks, but the cost was severe. That experience influenced later risk calculations. A successful campaign analysis must therefore treat Bunker Hill not as an isolated patriotic legend but as a data point commanders carried forward when Dorchester Heights presented another fortified-height problem.
Evidence basis: U.S. Army CMH — Revolutionary War Army History Trails
Washington inherited a coalition and had to turn it into an army
When George Washington took command, the forces around Boston came from several colonies with different enlistments, structures and supply systems. Standardizing command, maintaining manpower and surviving expiring terms were strategic tasks. The campaign’s military transformation is visible in the difference between the ad hoc April mobilization and the more deliberate March 1776 operation on Dorchester Heights.
Evidence basis: U.S. Army CMH — Revolutionary War Army History Trails
Ticonderoga’s guns changed what the siege could accomplish
The arrival of heavy artillery after Henry Knox’s winter transport gave Washington options that local militia muskets could not provide. Artillery made commanding heights more dangerous to the British harbor position. Logistics thus connected the northern frontier to Boston: captured material became campaign leverage only after an extraordinary movement over distance.
Evidence basis: U.S. Army CMH — Revolutionary War Army History Trails
Evacuation ended the campaign but preserved Britain’s main army
The British departure on March 17, 1776 was an American strategic victory. Yet the fleet carried Howe’s army away rather than surrendering it. The next major contest shifted to New York, where naval mobility and larger British forces created a different problem. Bellum’s campaign architecture therefore ends Boston by opening the path to New York, not by implying the war paused after the city was recovered.
Evidence basis: U.S. Army CMH — Revolutionary War Army History Trails
Frequently Asked Questions
How long did the Siege of Boston last?
The siege began after the fighting at Lexington and Concord in April 1775 and ended when British forces evacuated Boston in March 1776.
Source basis: NPS — The Siege of Boston Hub
Why was Dorchester Heights decisive?
The fortified heights threatened British positions and shipping in Boston, making evacuation the safer British choice.
Source basis: NPS — The Siege of Boston Hub
Was Bunker Hill an American victory?
British forces took the ground, so the battle was a British tactical victory, but the heavy cost demonstrated that colonial forces could sustain a major fight.
Source basis: NPS — The Siege of Boston Hub
How did artillery reach Boston?
Henry Knox organized the movement of captured artillery from the Lake Champlain region to the Boston lines during the winter of 1775–1776.
Source basis: NPS — The Siege of Boston Hub