(Just for fun): The 1911 Canadian-American Reciprocity Treaty is ratified

[The Mikado]

This attempt at free trade between the USA and Canada failed because US Speaker of the House Champ Clark, in supporting it, claimed that it was the first step towards a USA annexation of Canada. In the 1911 Canadian election, Robert Borden's Tories successfully convinced the electorate that free trade with the US was a stalking horse for American annexationism, in part due to Champ Clark's quote, and swept into power and ditched the free trade agreement. USA and Canada wouldn't establish free trade until the 1990s with NAFTA.

All I'm asking here is would free trade between the USA and Canada from the 1910s onward have the sorts of effects Champ Clark wanted and Robert Borden feared? Would it, in fact, have been the first step towards American annexation of Canada? (I very much doubt it) Barring annexation, how WOULD US/Canada relations look in the world in which they have had a free trade pact for over a century by this point?