Allen, Ethan (1738–1789), a military leader in the American Revolution and a Vermont patriot. His capture of strategic Fort Ticonderoga was one of the first American victories of the Revolutionary War. Allen, more than any other man, was responsible for Vermont's becoming a separate state.

Allen was born in Litchfield, Connecticut. Little is known of his early life. After serving in the French and Indian War in 1757, he invested in a farm and a smelting business. In 1769 he settled in the New Hampshire Grants (later Vermont) and was soon involved in the dispute over the territory, which was claimed by both New York and New Hampshire. To defend their claims, the Grants settlers formed a militia called the Green Mountain Boys, with Allen as its commander.

In May, 1775, Allen and 83 Green Mountain Boys, with Colonel Benedict Arnold of Connecticut, forced the surrender of British-held Fort Ticonderoga without loss of life. In September he led a handful of men in an attack on Montreal, but was captured and held prisoner by the British until exchanged in 1778.

Allen returned to Vermont, which had declared itself a state, independent from both New York and New Hampshire. Although a colonel in the Continental Army and a major general of militia, Allen confined his activities to seeking recognition of the new state by the Continental Congress. He and his brother Ira secretly attempted to make peace with Britain on behalf of Vermont, 1780–83, probably to force Congress to grant statehood.

Allen wrote several works on the Vermont dispute, a narrative of his British captivity, and a book on deism.

Ira Allen (1751–1814) was born in Cornwall, Connecticut. Moving to the New Hampshire Grants in 1772, he became active in the independence movement with his brothers, Ethan and Levi. Allen drafted the Vermont constitution, 1777, and was elected first treasurer of Vermont, 1778. He wrote Natural and Political History of the State of Vermont (1798).