In the first constitution of the United States in 1781, the nascent Articles of Confederation, there is a condition stating that if Canada ever does agree to become a member of the United States, they will automatically be accepted.
Canada is the only country, though, as any other colony, will require the consent of the other states.
Inspired Pizza
Apparently, Hawaiian pizza was invented in Canada by Greek Canadian entrepreneur Sam Panopoulos back in 1962. Or at least, Panopoulos has claimed to be the creator, but so have a few others.
Panopoulos loved Chinese dishes that combine sweet and savory flavors, and so he also decided to experiment by combining different ingredients to pizza, including pineapple and ham.
Border Patrol
Every six years, a 20-foot-wide section of the border between Canada and the US is deforested. This includes 5,525-miles of mountains, forests, and remote islands.
While it is supposed that very few people will actually stumble upon this area, this labor-intensive process is still performed as a means of ensuring that anyone who reaches the border knows where they are.
Political Animal
As ridiculous as this may sound, there was a satirical political party called The Rhinoceros party that was actually registered in the Canadian elections. They have campaigned on nullifying the law of gravity and promoting 'higher' education by building taller schools. With their slogan being "a promise to keep none of our promises."
The Rhinos even went on the win a surprising 1.01% of the vote in the 1980 election.
Contested Territory
There is a small island in the middle of the Arctic called Hans Island that is a disputed territory between Denmark and Canada. The two countries' have taken the dispute all in good stride.
Every once in a while, each country sends in a military team to dismantle the others' flagpole and upraise their own, leaving a gift of Canadian whiskey or Danish schnapps for the next team.