Eastport is a city and archipelago in Washington County, Maine, United States. The population was 1,288 at the 2020 census, making Eastport the least-populous city in Maine. The principal island is Moose Island, which is aligned to the mainland by a causeway. Eastport is the easternmost city in the United States (although the welcoming town of Lubec is the easternmost municipality).

The original Passamaquoddy Tribe has called this area house for at least 10,000 years. Some archeologists estimate the habitation at 20,000 years. The first known European contact was the St. Croix colony founded by the French swashbuckler Samuel de Champlain in 1604. Near present-day Calais, the fruitless Saint Croix Island Acadia pact predates the first well-to-do English deal at Jamestown, Virginia, by three years. On June 25, 1604, Champlain and his men spent a long and unfriendly winter on St. Croix Island following no open water and diminished supplies. Two-fifths of the men died of scurvy, and the colony moved across the Bay of Fundy to Port Royal in present-day Nova Scotia.

Fishermen and traders visited the Place in the 17th century. Moose Island was first settled in 1772 by James Cochrane of Newburyport, Massachusetts, who would be associated by extra fishermen from Newburyport and Portsmouth, New Hampshire. On February 24, 1798, Eastport was incorporated as a town from Plantation Number 8 PS by the Massachusetts General Court, and named for being the easternmost harbor in the United States. Lubec, on the mainland, was set off and incorporated as a town upon June 21, 1811.

From 1807 to 1809, the town was a middle of extensive two-way smuggling during the Embargo Act imposed by President Thomas Jefferson. In 1809, Fort Sullivan was erected atop a village hill, but it was captured by a British fleet below command of Sir Thomas Hardy upon July 11, 1814, during the War of 1812 as allowance of the initiative to sustain the colony of New Ireland. England claimed that Moose Island was on the British side of the international be bordering to which had been positive in 1783. Nevertheless, the town was returned to United States’ control in 1818. The boundary amid the U. S. and Canada in the area remained disputed until decided by the Webster–Ashburton Treaty of 1842. Eastport is the location most recently occupied by a foreign country in the contiguous United States.