I've been envisioning a depiction of a civil-war era Union solider alongside a Canadian soldier of the same era, but I can't find any good info on what such a Canadian soldier would have looked like. Any ideas?
I highly recommend J.L. Summers and René Chartrand, Military Uniforms in Canada, 1665-1970 (Ottawa: National Museum of Man, National Museum of Canada, 1981). This website, while a seller of replicas, contains extracts from Military Uniforms in Canada, 1665-1970 (see The Victorian Soldier).
Canadian Military Heritage (a series of three volumes conveniently converted into a website) might also be of interest. It provides an overview of Canadian military history and includes illustrations and photographs of uniforms. Volumes 2 and 3 would be the most relevant to your question.
Generally during this period, Canadian units would mimic the uniforms of similar British units.