Following the outbreak of the war, British authorities enlisted Loyalist merchant Ichabod Jones to supply the troops who were under the Siege of Boston.

Two of his merchant ships arrived in Machias on June 2, 1775, accompanied by the British armed sloop HMS Margaretta (sometimes also spelled Margueritta or Marguerite), commanded by Midshipman James Moore.

[8][9] The besieged British were led by General Thomas Gage and Admiral Samuel Graves, and both did business with the people of Machias.

Gage required lumber to build barracks for the additional troops arriving in the besieged city,[10] and Graves wanted to recover the guns from HMS Halifax shipwreck, which had been intentionally run aground in Machias Bay by a local pilot in February 1775.

There was an inconsequential exchange of gunfire with the militia men who were located on the shore, and Moore was able to raise anchor and travel to a safe anchorage.

[18] After escaping the Machias men, Margaretta was forced to jibe into brisk winds, which resulted in the main boom and gaff breaking away, crippling its navigability.

Since Unity was a much faster sailing vessel, O'Brien's crew quickly caught up to the crippled Margaretta, while Falmouth Packet lagged behind.

The remaining crew members of the British schooner were held at Machias for a month, then handed over to the Massachusetts Provincial Congress.

[23] The Machias community expected retaliation by the British Empire, and immediately petitioned to the Massachusetts Provincial Congress for guidance, supplies, and assistance.

Jeremiah O'Brien immediately outfitted one of the three captured vessels with breastwork,[25][26][27] and armed it with guns and swivels that were taken from Margaretta, and changed its name to Machias Liberty.

Jeremiah O'Brien and John Lambert built a twenty-gun ship and began privateering under an American letter of marque.

[31] The British naval command was continually frustrated by the use of Machias as a staging point for militia actions in Nova Scotia.

There is a widely told story that Machias men erected a Liberty pole after meeting in the Burnham Tavern to discuss the battles of Lexington and Concord.

This story, which persists in modern history books and travel guides,[32] has been shown to be an 1831 fabrication by Machias resident John O'Brien.

There is no mention of the Liberty pole in any earlier accounts, including the official report sent by the residents of Machias in 1775, and the letters of other participants in the events.