The Boston campaign was the opening campaign of the American Revolutionary War. The campaign was primarily concerned with the mobilization of Patriot militia units, and their transformation into a unified Continental Army. The campaign's military conflicts started with the Battles of Lexington & Concord on April 19, 1775, in which militias turned out according to plan to interdict and harass the British attempt to seize military stores and leaders in Concord Massachusetts. The entire British expedition suffered significant casualties during a running battle back to Charlestown against an ever-growing number of militia.
The accumulated militia surrounded the city of Boston, beginning the Siege of Boston. The main action during the siege, the Battle of Bunker Hill on June 17, 1775, was one of the bloodiest encounters of the entire war. There were also numerous skirmishes near Boston and the coastal areas of Boston, resulting in either loss of life, military supplies, or both.
In July 1775, General George Washington took command of the assembled militia and transformed them into a more coherent army. On March 4, 1776, the Patriot army fortified Dorchester Heights with cannon capable of reaching Boston and British ships in the harbor. The siege (and the campaign) ended on March 17, 1776, with the withdrawal of British forces from Boston. Boston celebrates March 17 as Evacuation Day.
