Opinion | The Fantasy of Annexing Canada Has a Long and Mortifying History

President Trump’s creepy remarks about Canada as “our cherished 51st state” may seem to have descended, bafflingly, from the clear blue sky.But American designs on Canada have a long history, predating even our independence and featuring some very familiar names.

“You are a small people,” concluded one early overture, “compared to those who with open arms invite you into a fellowship.” The approaches have changed over time, but the courtship has invariably played out with all the grace and romance of Pepé Le Pew on the trail of Penelope Pussycat.On several occasions, it has blown up in our faces.

“Alas, Canada, we have had misfortune and disgrace in that quarter,” John Adams warned some 250 years ago.As another president now hints at a northern expansion, we might care to remember the humbling earlier forays.In October 1774, the First Continental Congress resolved to dispatch an appeal to Quebec, which was then essentially a synonym for Canada.

Over 18 eloquent pages, the letter enumerated the rights of a free people.Though it urged no acts of hostility, it reminded the Canadians that they could expect no better treatment from their common sovereign than did their American counterparts.

Might they care to travel — “in order to complete this highly desirable union” — to Philadelphia for the next Congress, in May? To the high-minded rhetoric was added a prod: Canada would be wise to count the rest of North America among its “unalterable friends” rather than its “inveterate enemies.”Though no Canadian delegates materialized in Philadelphia that May, Congress remained undeterred.A new letter went out “to the oppressed inhabitants of Canada,” this one drafted by John Jay.

British rule, the letter argued, reduced Canadians to slavery and endangered their religious freedom.“We can never believe that the present race of Canadians are so degenerated as to possess neither the spirit, the gallantry, nor the courage of their ancest...