maus we used to go over the bridge at Calais into Saint Stephen in Canada - even in 2004 (and we went over regularly!). Not once ever asked for passport/driver's license at border checkpoint.
Quoddy headlight is in Maine, so you shouldn't have gone through any border area.... Were you maybe going to Campobello Island - that has a border checkpoint IIRC.
Here's from an official guide:
Q: What do I need to cross the border to Canada?
A: Effective June 1, 2009 a PASSPORT BOOK or PASSPORT CARD will be required to cross between the USA and CANADA. [Lubec, Maine - Campobello, New Brunswick]. For an expedient and pleasant crossing experience, please consider a smile, no hat, no sunglasses. Children under 18 need a birth certificate if traveling with both parents while a single parent needs a notarized release from the other parent. Current vaccination papers are required for pets. A smile, no sun glasses at the gate and a basically empty vehicle will help the process. You will be asked where you live, where you are staying and if you have tobacco, firearms, alcohol and any gifts or goods that you will be leaving across the border. Border crossings are at Lubec/Campobello and Calais/St. Stephen.