Fort Ticonderoga was captured by American forces in May 1775, giving the revolutionaries valuable artillery for the campaign against British forces in Boston.
The fort stood on Lake Champlain at a strategic route between New York and Canada. Ethan Allen and the Green Mountain Boys, joined by Benedict Arnold, surprised the small British garrison on May 10, 1775. The garrison surrendered without a major battle.
The captured weapons included heavy cannon. Henry Knox later organized the difficult transport of these guns from Ticonderoga to the Boston area during the winter of 1775–1776. Placed on Dorchester Heights, the artillery threatened Boston and contributed to the British evacuation in March 1776.
The capture was strategically important, but it did not by itself end the Boston campaign. It also involved overlapping claims of authority and credit: Allen led the initial assault, Arnold had a separate commission, and the Continental Congress later placed the fort under Continental control. The fort’s location made it important again during later campaigns in the Revolutionary War.