It might streamline things for you. A valid passport tells them you’ve jumped through a bunch of government hoops already.
Jesus, digs, you can’t just pet some guy’s moose. {Walks off grumbling about presumptuous US Americans.}
Yes, carry your passport. If you don’t, I’m sure that the assumption is, “this guy is not going to go home and will stay illegally.” Why? Some years ago, we had a few problems with people washing up on our shores without papers and claiming refugee status or some other kind of asylum later. As it turned out, they weren’t refugees–they just wanted in, without going through proper channels–and to bolster their claim, they had destroyed their papers while at sea.
Bring your passport. It will make things so much easier.
Yeah. You know those signs warning about the danger of moose?
We just tell people they’re road accidents.
Here’s a twist - the Québec version:
My hometown is close to the Vermont border (40-50 mins or so), and border crossing for gas and shopping is a rather frequent occurrence. It is almost always, however, accompanied by a trip to a bookstore and/or a movie theatre: because getting English-language movies in theatres in the Sherbrooke area is actually rather rare. It’s a combination of lack of demand and sheer stupidity on the part of the theatre owners, so anglophones (or francophones who prefer to see movies in the original language) cross the border into Newport, catch a movie, stock up on whatever, gas up and head home. The alternative is a drive up to Montreal, which is about an hour and a half away and involves more traffic and bridges.
We don’t really fly flags at malls in Canada. It’s not part of our custom.
It’s also very rarely the case that cross-border shopping would make sense for Americans, even when the Loonie is weak. It’s no surprise that retailers don’t try to take advantage of an opportunity that doesn’t exist.
Well, for certain things… I’m thinking of the hundreds of shops in Windsor, Ontario selling Cuban cigars. Can’t get 'em in the States, and Detroit is just over there.
Sault Ste. Marie, Michigan is also an interesting exception, where the larger and more prosperous city is on the Canadian side. People have pretty much figured out on which side of the border something is cheaper/more readily available. Gas & booze - US. Specialty groceries - Can.
In response to an earlier remark, it’s not that all of our malls fly flags. Those that do, don’t seem to have much problem including a US flag in with the rest. I don’t think I’ve seen anywhere in Canada that flies an American flag and doesn’t fly at least a Canadian flag; that would be weird.
Folks in Thunder Bay, Ontario, pop down to Duluth and Minneapolis, MN, to do the tourist thing and do some shopping while they are at it. The price difference is usually not that big a reason, if any, but the product variety and availability is a very big reason. There’s a lot more stuff down thar.
Thunder Bay: “We don’t have it, but we can order it in.”
Duluth or Minnie: “We have it in nine sizes and four colours.”
The only cases I can think of are if those Americans wanted to buy real Cubans, or 18-20 yr olds wanting booze. And I could see how both scenarios could cause problems at customs. Now, on our other border it’s pretty common for Americans to go shopping in Mexico.
Psst … the US embassy does, as do American consulates across Canada. 
All year I plan for our summer road trip to the US. We don’t do it for shopping, but it is an added bonus. Many art supplies are 50% or more cheaper than they are here.
Last summer I think I spent $400 on what would have cost me $1200 here.
. . . or a good time with a prostitute (it is legal here, although a lot of things associated with it are not legal at this time).
I think that falls under the category of ‘real Cubans’.