What's so civil about a civil war? Only that "civil" can mean of or pertaining to citizens or communities of citizens. Hence civil wars are wars within communities, within states.
It's a term the American historian Alan Taylor uses repeatedly and cleverly. In 2010 he published The Civil War of 1812. That's a civil war in his story because many Canadians fought on the American side, New Englanders who opposed the war struggled with western Americans who promoted it, Indigenous nations were pulled into both sides, and groups like the Irish tried to make it an aspect of their own national struggles. It's probably the best book inspired by the War of 1812 bicentennial, offering a detailed history of the war while constantly alive to local details and discordant themes that rewrite the dominant narrative.
More recently Taylor has published American Civil Wars: A Continental History 1850-1873. It is obviously dominated by the American Civil War (indeed, it's part of a multi-book "continental history of the United States" he has been writing). But Taylor emphasizes that at this time Mexico was also engaged in a civil war, one that included both American and French invasions, as well as a violent struggle between Mexico's conservative aristocracy and its burgeoning liberal underclass asserting the rights of poorer and even mixed race Mexicans. He is determined to bring in Canada too. There was no war over Canada, so he makes the most of Canada's need to prevent "violent division" between Francophones and Anglophones (plus the American military threat) in order to incorporate the national- building struggle of Canada into the continental story of civil strife in all three societies.
It's all very well done. Taylor is as good at seizing the broad lines and big socio-economic themes as at summarizing campaigns and battles. And he shapes it all with remarkable mini-biographies, like those of Jane McManus and Jane Cannon, two mid-century American women to whom he devotes the opening pages of this book -- and, later in the story, Mary Ann Shadd Cary. He also takes pleasure at more than one point in pointing out repeated disproofs of the eternal American faith that Canadians are forever begging to be given "freedom" through annexation to the American colossus.
I'm well disposed to his Canadian coverage not only because he footnotes me often enough for some of his vivid details. His spotting of continent-wide themes is valuable and fresh. But really, his Canadian coverage is brief in comparison to the Mexican material, let along the American material. The bulk of his Canadian material draws on the mid-20th century histories of Creighton, Morton, and Careless, plus Richard Gwyn's Nation Maker, a well made book but one that draws most of its interpretative framework from the earlier consensus.
I can't help but lament the thinness of the Canadian historical work compared to recent American and Mexican materials, which keeps him from giving a richer account of the issues being struggled over here. There just is not that much new political/diplomatic/military scholarship about mid-nineteenth century Canada from which he can draw. His brief notes on indigeneous policies and resistance are perceptive but very brief. On political matters, Macdonald comes out well without being hero-worshipped.