The Battle of Machias occurred when a group of American colonists in Machias, Maine, mounted an attack on the British Royal Navy ship, the Margaretta. This vessel had been dispatched to enforce British authority over trade and fishing in the region. Tensions in the area had been escalating due to British enforcement of the Navigation Acts and the colonists' discontent with how their rights were being undermined. Col. John Allen, a local leader among the patriots, galvanized the citizens of Machias to oppose British naval activity.

On June 11, 1775, local militia and other patriots armed themselves and launched a surprise attack against the Margaretta. Utilizing small boats and their knowledge of the local waters, they managed to board the British ship, where an ensuing battle took place. The patriots' preparedness and determination proved decisive, resulting in the Margaretta’s capture. This successful engagement not only bolstered patriot morale but also illustrated the willingness of colonists to reject British naval dominance.

The aftermath of the battle saw the captured Margaretta used by patriot forces to combat further British naval incursions. It also inspired similar naval engagements in other colonies, signaling the emergence of organized maritime resistance against British control. The Battle of Machias is often remembered as a pivotal moment in establishing American naval power during the Revolution.