Vermont kept small garrisons in the forts at Rutland, Castleton, and Pittsford, and the militia in readiness to turn out in force when required, while two companies of rangers patrolled the frontier to watch the movements of the enemy. Her troops responded promptly to calls to act against the common enemy, as was proved when, to intercept the marauding force of Sir John Johnson, which had been ravaging the Mohawk Valley, Governor Clinton marched with the militia of Albany to Lake George, and sent an express to the commanding officer at Castleton to meet him at Ticonderoga with such force as he could muster. A day later, Ebenezer Allen, now major of the Vermont rangers, sent him word that he had arrived at Mount Independence with more than two hundred men, and was expecting a hundred more to join him, trusting that the governor would furnish boats to transport them across the lake. Johnson slipped by to the northward and escaped, but Clinton wrote to the New York delegates in Congress that the punctuality of the "militia of the Grants in complying with his request with 240 men did them great honor."

When, early in October, 1780, the British, as already stated, came up the lake with eight large vessels and more than a thousand men, their designs were against New York and not against Vermont, as the British policy was then to favor Vermont, with a view to future operations. Fort Anne was taken, and Fort George shared the same fate after the greater part of its garrison, consisting of eighty men of Warner's Continental Regiment under Captain Chipman, had been killed or captured by a superior force of the enemy, which they encountered when expecting to meet only a scout that had driven in one of their messengers sent to Fort Edward.

Marking its course with destruction, this invasion of the enemy created such a panic on the New York frontier that but few men could be raised there to oppose it. In this alarm, Governor Clinton so far acknowledged the existence of the "ideal Vermont State" as to direct an officer to write to Governor Chittenden for assistance.[87] He was immediately answered that the militia of the State were at the North, but the militia of Berkshire, which had been sent for, would be forwarded on their arrival.

Before the pacific intentions of the British were known, the militia of Vermont were called out. They immediately mustered at Castleton under General Ethan Allen, and the assembly, then in session at Bennington, adjourned, that the members might take the field. Vermont, late in October, agreed to the truce, when her militia were dismissed, save a small force of scouts.

During the progress of this invasion occurred the last important incursion of the Indians within the limits of Vermont. While Carleton's force swept with purposed harmlessness past the western border of Vermont, an expedition set forth against Newbury, on the Connecticut, with the putative object of capturing a Lieutenant Whitcomb, who, while scouting on the Richelieu some years before, had mortally wounded and then robbed the British General Gordon. The force was commanded by Lieutenant Horton of the British army, seconded by a Canadian named La Motte, aided by one Hamilton, an escaped prisoner of war, who had been in Newbury and Royalton on parole of honor during the previous summer. It consisted of 300 men,[88] all but seven of whom were Indians. It is probable, from this preponderance of the savage element in its composition, that the real purpose of the expedition was the rapine which it so successfully accomplished.

Guided by old warriors, who had often followed this ancient warpath of their people in the days when their onslaughts were the constant dread of the New England frontiers, the party took its way up the Winooski, past tenantless houses and deserted farms, on whose broad intervale meadows the timid deer now grazed undisturbed. Then it came to where the wild stream wound through the unbroken wilderness; now among the frost-painted forest of deciduous trees, and now in the black shade of evergreens. Among the great pines that then clad the narrow valley, where now stands the capital of the State, they overtook and made prisoners two hunters from Newbury. These told the leaders that the people of their town were expecting an attack, and were prepared for it. Upon this they turned southward, and, following a branch of White River, on the 16th of October fell upon Royalton and neighboring towns.

The attack was at first conducted in perfect silence, till the alarm of it spread among the inhabitants; then the infernal clamor of the warwhoop resounded among the hills that had so long been strangers to its echoes, giving to the panic another terror.

Burning, pillaging, and making prisoners as they swooped with the celerity of falcons upon one and another isolated homestead or defenseless hamlet, they killed four persons, captured twenty-five others, and destroyed quantities of stock and garnered harvests.

As they drew off with prisoners and booty, Mrs. Hendee, the brave young wife of a settler, followed them, so earnestly pleading for the release of her little son that he was restored to her; and, upon her further entreaty, nine other small lads were set free.

The alarm soon reached the settlements on the Connecticut, and a force of 250 men were mustered, and, under command of Captain House, began a vigorous pursuit of the enemy in the night. Before daybreak they came up with the rear-guard of the marauders, who fired upon them, wounding one man. The fire was returned with better effect, killing one Indian and wounding another. The Indians then sent a prisoner to House with a threat that, if they persisted in the attack, the captives would all be immediately killed.