The Continental Association attempted to enforce the boycott on 2 March 1775 against a shipload of sail, rope, and rigging for loyalist shipbuilder Captain Samuel Coulson of Portland by demanding the delivery ship leave port.

[2] Canceaux was prepared to prevent the small boats from boarding; but Thompson's militia captured the warship's captain, Lieutenant Henry Mowat, on 9 May 1775 while he was ashore arranging church services for his crew.

Mowat was allowed to return to his ship, but his demand to arrest Thompson was refused, and the assembled militia forced Canceaux to leave port on May 15.

[1] Disappointed militiamen vented their frustration by looting the homes of Coulson and loyalist Sheriff Tyng before returning to their inland communities.

The Massachusetts House of Representatives promoted Samuel Thompson to Brigadier of the Cumberland County, Maine militia on 8 February 1776 in recognition of his initiative following the battles of Lexington and Concord; and the spruce trees his men carried provided inspiration for adoption of the Pine Tree Flag as the Massachusetts naval ensign in April 1776.