Built in 1775 immediately after the first naval battle of the American Revolution took place offshore, Fort Machias was a four-gun battery that guarded the mouth of the Machias River in cooperation with Fort Foster upriver. The British destroyed it that same year, but it was refortified in 1777 and remained part of the protection of the river and its towns through the American Revolution, the War of 1812, and the Civil War, even as its layout changed several times over the 90 years it was active on this site. From 1808 to 1818 it was a four-gun crescent-shaped earthwork fort, and in 1814 the British captured it and burned the barracks before returning it in 1818. Next to the ruins of Fort Machias, Fort O'Brien was built in 1863 as a Civil War five-gun earthworks fort, with well-preserved earthworks overlooking Machias Bay, and in 1923 the United States Government deeded the site of both forts to the State of Maine. In the middle of the Civil War era earthworks stands a bronze cannon known as a Napoleon, or 12-pounder, which fired 12-pound cannonballs, spherical case shot, or cannister; the tube weighs 1216 pounds, was made by the Ames Manufacturing Company of Chicopee, Massachusetts, in 1862, originally sat on a wooden carriage weighing another 1128 pounds, and in optimal conditions could fire a ball 1600 yards, enough to reach across the mouth of the Machias River. Near Route 92, a bronze tablet recalls a June 1775 gathering in which the men of Machias, pressed to supply their country's enemies, debated their course until Benjamin Foster leaped across a brook and called those willing to stand by their countrymen and their country's cause to follow him, after which almost the entire assembly did so and the settlement committed itself to the Revolution.