The capture of Fort Ticonderoga occurred during the American Revolutionary War on May 10, 1775, when a small force of Green Mountain Boys led by Ethan Allen and Colonel Benedict Arnold surprised and captured the fort's small British garrison. The cannons and other armaments at Fort Ticonderoga were later transported to Boston by Colonel Henry Knox in the noble train of artillery and used to fortify Dorchester Heights and break the standoff at the siege of Boston.

The Fortification of Dorchester Heights was a decisive action early in the American Revolutionary War that precipitated the end of the siege of Boston and the withdrawal of British troops from that city.