Brigham was once the most commonly found pipe maker in Canadian stores. The factory was in Toronto, and pipes were distributed nationally through department stores, haberdasheries, tobacconists and also at regional and national trade shows and events like the Canadian National Exhibition, the Toronto Sportsman's Show (where they annually sold their "Sportsman" line of pipes).
As a result, these pipes are fairly common in Canadian antique shops/malls.
Most, not all, Canadian Brigham pipes are marked "Made in Canada" or "Canada" somewhere on the shank. Also, most of these pipes have an aluminum tenon and vulcanite stems versus the delrin tenons and acrylic stems being used now in the French and Italian production. As I understand it, today Chinooks and higher grade pipes are being made in St. Claude, France at the ChaCom factory; and all grades under the Chinook are being made in Italy.
So, to answer your question in a round about way Quincy, if you have a pipe with a vulcanite stem, and an aluminum tenon, there is a high likelihood that it was made in Canada, regardless of stem marking.
-- Pat