The U.S. government is ending a more than century-old friendly arrangement on the Canadian border as the two countries feud.

But Mr. Trump’s criticisms have upended the business-as-usual atmosphere at the border. Map along the Canada-United States border highlighting Coutts, Canada and Sweet Grass, United states.

It's unknown exactly how many pounds of drugs cross the border into the United States. Mr. Trump claims "tremendous" amounts of fentanyl pour into the country through Canada, but last year ...