Some companies served in the American Revolutionary War, including notably when the Green Mountain Boys, led under the command of Ethan Allen who was assisted by Benedict Arnold, captured Fort Ticonderoga on Lake Champlain on May 10, 1775, and invaded Canada later in 1775.

Allen joined the staff of the Northern Army of New York's Major General Philip Schuyler and was given the rank of lieutenant colonel.

[4]: 143–145 [5]: 220 [6] The original Green Mountain Boys were a militia organized in what is now southwestern Vermont in the decade prior to the American Revolutionary War.

New York was given legal control of the area by a decision of the British crown and refused to respect the New Hampshire titles and town charters.

With several hundred members, the Green Mountain Boys effectively controlled the area where New Hampshire grants had been issued.

When the American Revolutionary War started in 1775, Ethan Allen and a troop of his men, along with Connecticut Colonel Benedict Arnold, marched up to Lake Champlain and captured the strategically important British military posts at Fort Ticonderoga, Crown Point, and Fort George, all in New York.

During the Haldimand Affair, some members of the Green Mountain Boys became involved in secret negotiations with British officials about restoring the Crown's rule over the territory.

A remnant of a Green Mountain Boys flag, believed to have belonged to John Stark, is owned by the Bennington Museum.