The word canuck first appeared in 1835 as a derogatory American reference to French Canadians working in the lumber camps of Maine.
Today it means any Canadian and is no longer an insult unless used by non-Canadians to describe our French brothers.
It’s most likely a combination of the French word for canoeman, canaque, with the “uk” exaggerated from a very common ending to Indian nouns like Tuktoyuktuk.
But the word could also be from Canada/Kanata, the name derived from a First Nations word meaning “a collection of huts”, abbreviated with “uk” as a suffix.
Over a million French Canadians migrated to New England during the second half of the nineteenth century.
Jack Kerouac’s family was among them.
Johnny Canuck, the cartoon character, dates from 1869 and was used for propaganda during the Second World War.
I was told as a boy growing up in eastern Montana that canuck came from the canadians comming into Montana with thier coins and jamming all the coin operated vending machines. They would then get a refund in Us coins, they would go home with a profit and be known as coin crooks (canucks)