Thanks for the invitation ... but no thanks

Here's a piece of history. The US invited Canada to join up with them - way back in 1777!

The 11th article of the Articles of Confederation - the first constitutional document of the then fledgling country - states:

Canada acceding to this confederation, and adjoining in the measures of the United States, shall be admitted into, and entitled to all the advantages of this Union; but no other colony shall be admitted into the same, unless such admission be agreed to by nine States.

The Articles of Confederation were superseded by the US Constitution, so the invitation for the norther neighbours is probably not still open ... But I saw a satirical articles at Uncyclopedia that says Canada has gone to court to argue that the AofC are still in force, so we should be let in.

If you want to read a more reality-based entry on the AofC, check out Wikipedia.