The Americans blow up the fort and then abandoned it, while the British landed with this force totaling 2,000 regulars.
The British officers then made plans to capture the frigate U.S.S. Adams, which had moved up river to the town of Hampden about thirty miles from Castine. The Americans were hoping they would have enough time to repair the frigate there.
On the morning of September 3rd the British landed three miles below Hampden and quickly defeated the local militia of about 1,400, with a loss of one killed and eight wounded and one missing. The American Captain set the Adams on fire as so it would not be captured and retreated with her crew. After seizing the twenty cannon, the British forces continued up river to Bangor, it was here that a British officer reported "The inhabitants who had opposed us at Hampden, threw off their Military character, and as magistrates, select men, &c made an uncoditional surrender of the town." The men that surrendered were now released on parole.
On September 9th the British forces returned down river to the town of Castine. Also on the 9th of September Lieutenant - Colonel Pilkington with battalion companies of the 29th Foot and remaining men of the 60th moved up to Machias. This was the only place the American troops occupied between this and Passamaquoddy Bay. On the night of September 10th the British landed and chose to go through the thick woods so they could approach the fort from the rear. When the British advance guard arrived in the morning they found that the Americans had left. The British now occupied Machias without firing a shot. The British were preparing to advance inland on the 13th of September when they recieved a letter of capitlation from the senior American militia officers of the county. The letter read ...
"The forces under your command having captured the forts in the neighbourhood of Machias and taken possession of the territory adjacent within the county of Washington, and the situation of the County being such between the Penobscot River and Passamaquoddy Bay as to preclude the hope that an adequate force can be furnished by the United States for it's protection. We propose a capitulation and offer ourselves and on behalf of the officers and soldiers of the brigade within the County of Washington to give our Parole of honor that we will not directly or indirectly bear arms, or in any way serve against His Britannic Majesty King George ... during the present war between Great Britain and the United states; upon we have your assurance that while we remain in this Situation and Consider ourselves under British Government until further Orders, we shall have the safe and full enjoyment of our Private property, and be protected in the exercise of our usual occupations."
The British accepted the capitulation and this brought the campaign to a close. Trade between the ports of Nova Scotia, New Brunswick and New England opened again following Rear - Admiral's proclamation of September 15th it read ...
"The territory lying between the bay of Passamquoddy and the river have been taken possession of by H.M.'s forces: all vessels clearing out from any port of H.M.'s North American provinces, for any port or place within the territory, including the port of Castine, and the ports and places situated on the east side of the Penobscot river, are to pass free and unmolested, to bring back cargoes of lumber and provisions; also any vessels being from the port of Castine with a licence issued from commanding officers of H.M's land and naval forces at Castine"
One other proclamation was issued jointly by Rear - Admiral Griffith and Lieutenant - General Sherbrooke it was to appoint a customs official at Castine and a new Governor for this new British territory.
No hostile acts were directed at the British forces in Maine, the people were too busy with uninterupted trade with Nova Scotia and New Brunswick to care about a war that they did not want in the first place.