Yeah, they'd probably start with BC due to tactical superiority (ie, not being surrounded).
Well, it's not so much that they wouldn't want to be surrounded (by Canada), it's that B.C. is probably militaristically the most important piece of land (to the US) in North America. It has the best ports for any kind of invasion/attack from the east: north korea, russia, china, ....
Actually, that's part of what started the 1812 war, and why Victoria is
WAY below the 49th parallel and is still in Canada; the British/Canadians also knew the military value that area had and fought pretty hard for it.
Also, as things are now, Vancouver is the
largest port on the
west coast of North/South America, and actually is only second to New York I think for largest port in North/South America.
So if the US were in a store that sold CDN provinces, BC by far would be the most expensive province -- regardless of resources, etc.