Fort O'Brien (Machiasport, Maine)

Machiasport · Maine · American Revolutionary War, War of 1812

Quick BriefFort O'Brien was established in 1775 immediately after locals led by Jeremiah O'Brien captured the British Royal Navy ship Margaretta in the Battle of Machias on June 11–12, 1775. The fort was built and destroyed three times over a 90-year period, serving as a critical river fortification during the American Revolution, War of 1812, and Civil War.
Coastal defenseOpen to visitors
Fort O'Brien, Maine

History & Significance

Established in response to the Battle of Machias (June 11–12, 1775), in which colonists led by Jeremiah O'Brien captured a British Royal Navy ship, this four-gun earthwork battery guarded the mouth of the Machias River throughout three major American conflicts. After its initial construction, the fortification was destroyed when British forces returned in 1777.

The fort was reoccupied by 1781 under the name Fort O'Brien. During the War of 1812, Captain John Leonard commanded the installation with fifty soldiers of the 40th U.S. Infantry; when the British approached after capturing Eastport and Castine, Leonard fired a volley from his guns, spiked as many as he could, burned the buildings, and retreated westward with British prisoners.

In 1814, the British destroyed the fortification and burned its barracks. A five-gun battery was installed in 1863 during the Civil War but saw no action. The fortification was deeded to the state by the federal government in 1923.

Key Facts

StateMaine
LocationMachiasport
Established1775
War / eraAmerican Revolutionary War, War of 1812
Current statusMuseum / Historic Site
Coordinates44.68944444, -67.39666667
NRHP reference69000024

Map

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🧳 Visiting

What you’ll see when you visit:

  • Earthwork ruins from American Revolutionary War and War of 1812
  • Historic fortification on Machias River
  • Reconstructed structures from multiple conflict periods
  • Museum exhibits on Maine's maritime military history
Best time to visitLate spring through early fall (May-September) offers pleasant coastal Maine weather; summer season aligns with the site's operating period.
Getting thereFly into Bar Harbor Airport (BHB), approximately 50 miles south of Machiasport.
From the nearest major airportBangor International Airport (BGR)🚗 95 mi by road⏱️ ≈ 2 hr 25 min drive

Sources

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