The Missaguash River (French: Rivière Missaguash) is a small Canadian river that forms the southern portion of the inter-provincial boundary between Nova Scotia and New Brunswick on the Isthmus of Chignecto. It had historic significance in the 18th century as the de facto border between French (to the west) and English-controlled territories.
The river's name is from the Mi'kmaq language, likely meaning "marsh river", in reference to the Tantramar Marshes through which it flows. The river flows south into Cumberland Basin. Its source is in the Missaguash Bog, several kilometres to the north.
About 1672 a small group of Acadians from Port Royal, led by Jacques Bourgeois, formed a settlement on the south bank of the Missaguash near its mouth named Beaubassin. The settlers reclaimed the salt marsh bordering the Missaquash for cultivation by constructing dykes to keep out the sea.
This village grew until 1750. The French priest Jean-Louis Le Loutre led Mi'kmaq warriors to burn down the village to force the Acadians to relocate to French-held territory north of the Missaquash. He wanted to bring French settlers together in a time of increasing national tensions with Great Britain. In the fall of 1750 the English army under Major Charles Lawrence established Fort Lawrence on the site of the burned village.
- The practice of burning one's own residences for military ends was not uncommon. For example, at this same time Le Loutre burned Beaubassin for military reasons, French officer Boishebert burned the French Fort Menagoueche on the Saint John River to prevent it from falling in the hands of the British and to allow Acadians to escape to the forest (see John Grenier. The Edge of Empire. Oklahoma Press. 2008. p. 179). As well, the British burned their military officers own residences at Annapolis Royal to help defeat the French, MI'kmaq and Acadian attacks during King George's War. (See Brenda Dunn. Port Royal/ Annapolis Royal. 2004. Nimbus Press).