Passamaquoddy Bay () is an inlet of the Bay of Fundy, between the U.S. state of Maine and the Canadian province of New Brunswick, at the mouth of the St. Croix River. Most of the bay lies within Canada, with its western shore bounded by Washington County, Maine. The southernmost point is formed by West Quoddy Head on the U.S. mainland in Lubec, Maine; and runs northeasterly through Campobello Island, New Brunswick, engulfing Deer Island, New Brunswick, to the New Brunswick mainland head at L'Etete, New Brunswick in Charlotte County, New Brunswick. Overview The exact demarcation of the border in Passamaquoddy Bay was a long-standing issue between the United States and Britain/Canada. Already the Treaty of Ghent, ending the War of 1812, included a provision for the appointment of "commissioners to divide the islands of Passamaquoddy Bay between the United States and Great Britain" (see John Holmes). Nevertheless, confusions and ambiguities on this issue persisted. The southern boundaries of the bay are sometimes confused since Deer Island sections off the large open waters of the bay; however, the terminology of the Passamaquoddy Bay Treaty of 1910 specifies that Passamaquoddy Bay runs south of Treat Island (one of the islands that now comprise the city of Eastport, Maine), between Campobello Island and Lubec, Maine: "Now, therefore, upon the evidence and arguments so presented, and after taking into consideration all actions, of the respective Governments and of their representatives authorized in that behalf and of the local governments on either side of the line, whether prior or subsequent to such treaties and award, tending to aid in the interpretation thereof, the High Contracting Parties hereby agree that the location of the international boundary line between the United States and the Dominion of Canada from a point in Passamaquoddy Bay accurately defined in the Treaty between Great Britain and the United States of April 11, 1908, as, lying between Treat Island and Friar Head, and extending thence through Passamaquoddy Bay and to, the middle of Grand Manan Channel, shall run in a series of seven connected straight lines for the distances and in the directions as follows." The largest community on Passamaquoddy Bay proper is St. Andrews, New Brunswick, but the twin communities of Calais-St. Stephen are sometimes included, despite being located on the St. Croix River. The city of Eastport, Maine lies between Passamaquoddy Bay and Cobscook Bay, to the city's west.