The Green Mountain Boys was a militia group formed by Ethan Allen to keep the New Hampshire Grants from becoming part of New York. During the American Revolution, they captured Fort Ticonderoga.
Present-day Vermont was once known as the New Hampshire Grants. It was called that because New Hampshire had granted the land to settlers. However, New York also claimed ownership of the area, and tried to enforce its laws on the residents.
Ethan Allen and others organized the Green Mountain Boys 1770 to help oppose New York sheriffs who tried to enforce laws. However, they also terrorized settlers who had been given grants from New York.
Shortly after the Revolutionary War began, the Green Mountain Boys, Benedict Arnold, captured Fort Ticonderoga. This was the first victory for American forces in the war, and provided valuable resources for the American forces. The 59 cannon and mortars from Ticonderoga were taken to Boston by a force led by Henry Knox and used in the Seige of Boston.
The group joined with the Continental Army, and participated in the failed invasion of Canada in 1775. Ethan Allen other members were captured in a failed attempt to take Montreal on September 25, 1775.
The Green Mountain Boys, under the leadership of Colonel Seth Warner, participated in the Battle of Hubbardton (July 7, 1777) and the Battle of Bennington (August 16, 1777), playing a key role in weakening the forces of General John Burgoyne.