Boston’s evacuation by British troops on March 17, 1776, is commemorated during America250’s anniversary events.
The event ended the Siege of Boston, an early major campaign of the American Revolutionary War. After American forces fortified Dorchester Heights with cannon brought from Fort Ticonderoga, British commander William Howe decided to withdraw rather than attack the newly strengthened position. British troops and loyalists left Boston by sea on March 17, 1776.
The date became known as Evacuation Day in Massachusetts. It is also St. Patrick’s Day, which helped the anniversary remain prominent in Boston civic tradition. In 2026, the date represents 250 years since the evacuation.
This event occurred before the Declaration of Independence was adopted. That timeline matters: the war had already begun at Lexington and Concord in 1775, while independence was formally declared several months after Boston was evacuated.