March 17 may be best known around the United States as St. Patrick’s Day, but in Massachusetts, it’s also known as Evacuation Day, when in 1776 British forces withdrew following the Siege of Boston, signaling a major victory for General George Washington in the Revolutionary War. Boston had been under siege since shortly after war broke out in April 1775, with periodic skirmishes occurring over 11 months. Washington’s decision to fortify an elevated piece of ground at Dorchester Heights, where a 115-foot marble tower stands today in commemoration, helped turn the tide.
With heavy cannons and artillery in place by March 1776, the British increasingly saw their position in the city as indefensible. Wishing to avoid a repeat of the Battle of Bunker Hill—a British victory, but with heavy losses—General William Howe ordered the withdrawal of 11,000 British troops on March 17. The Siege of Boston was finally at an end. Boston remained an important port city in the war effort, but it ceased to be a military target.
Now 250 years later, Evacuation Day continues to carry special significance. It is a symbol of Boston’s spirt of resilience and community when faced with adversity, and also historically significant as a watershed moment in the early years of the war. Evacuation Day became a legal holiday in Suffolk County in 1901, and one year later the Dorchester Heights Monument was completed. It recently underwent a $30 million renovation, reopening to the public in July 2025. The monument is one of several historic sites in and around the city dedicated to victory in the Siege of Boston, including the Bunker Hill Monument and Boston Common.
The National Park Service offers a map of Siege of Boston sites available here.
Main Image: Dorchester Heights Monument; Credit: National Park Service/P. Boyce
