Would losing Maine have transformed Anglo-American relations?

If Britain had retained Maine after the War of 1812, would it have caused another conflict or changed later Anglo-American relations?

Probably not by itself; Maine offered limited strategic and economic gain, though its loss would have changed American memory of the war and modestly strengthened Canada.

Retaining occupied parts of Maine and attaching them to Canada is judged unlikely, by itself, to produce another Anglo-American war. Maine's trade connections with Britain and limited resistance to occupation support that assessment. Losing Vermont, New Hampshire, or strategically valuable parts of New York is treated as a more provocative alternative. The assessment is explicitly provisional and outside the lecturer's specialist research area. Territorial loss could have changed American political memory of the War of 1812 and given opponents a lasting criticism of the president. It would also have given Canada more defensible territory and better access to the sea, with a limited change in the two countries' economic balance. Customs revenue from the actual British occupation helped establish Dalhousie University in 1818.