In the good old days, you used to be able to travel between Canada and the USA with little documentation. Birth certificates or driver's licenses were acceptable identification, and everything was nice and simple.
If you haven't had to cross the border lately, you might not know the rules have changed. Any border crossing between Canada and America will now require a proper passport.
Some Canadian provinces are implementing new Enhanced Driver's Licenses that may be a valid document. These are NOT your usual driver's license, and require a separate application to acquire.
It's best to have a passport, to be on the safe side.
