HistoryData
Historical ConflictMassachusetts

Boston campaign

The Boston campaign opened the American Revolutionary War, ending with British forces permanently evacuating Boston in March 1776.

Duration & Scope

1774 1776

2 years

Key Facts

Campaign start
April 19, 1775 (Lexington and Concord)
Campaign end
March 17, 1776 (British evacuation)
Duration
Approx. 11 months
Evacuation Day
March 17, still commemorated in Boston
Key turning point
Fortification of Dorchester Heights, March 4, 1776

Strategic Narrative Overview

The campaign opened with the Battles of Lexington and Concord on April 19, 1775, as militia harassed British troops in a running fight back to Charlestown. Colonial forces then surrounded Boston, laying siege to the city. The Battle of Bunker Hill on June 17, 1775, proved costly for both sides, ending in a Pyrrhic British victory. In July 1775, George Washington assumed command and began organizing the militia into a disciplined Continental Army.

01 / The Origins

Tensions between the British colonial government and Massachusetts colonists reached a breaking point in 1775 when British authorities sought to suppress growing resistance by seizing military stores and arresting Patriot leaders in Concord. This effort to disarm the colonial militia and neutralize opposition reflected broader British policy of tightening control over the restive Province of Massachusetts Bay, which had been under punitive governance since the Intolerable Acts of 1774.

03 / The Outcome

On March 4, 1776, colonial forces under Washington fortified Dorchester Heights overnight, positioning artillery that threatened both Boston and British ships in the harbor. Unable to dislodge the guns, British commanders chose to withdraw rather than risk another costly assault. On March 17, 1776, British forces and loyalist civilians permanently evacuated Boston, ending the siege and the campaign and delivering the Patriots their first major strategic victory.

Belligerents & Mobilization Analysis

Side A

1 belligerent

Kingdom of Great Britain
Key Commanders

Thomas Gage, William Howe.

Side B

1 belligerent

American colonial militia / Continental Army
Key Commanders

George Washington.

Outcome
Patriot victory; British forces permanently evacuated Boston on March 17, 1776

Kinetic Engagement Axis

Major engagements timeline (1774–1776)Timeline of major military engagements plotted chronologically.177417761775Battles of Lexin…Side B1775Battle of Bunker…Allied1776Fortification of…Side B

Scroll horizontally to view full axis. Events plotted relatively.

Side A victorySide B victoryInconclusiveDecisive / turning point

Location

Map of Boston, United StatesMap of Boston, United StatesBoston, United States