STANSTEAD, Quebec — Rue Dufferin, the main street in this town that hugs the US border, once bustled with Americans heading north to its pubs and antique shops. And from here, Canadians headed south to Vermont for cheaper gas and groceries. Many have family and friends on both sides.

Then the pandemic hit, and everything seemingly changed overnight. These days, Rue Dufferin has grown quieter, and US license plates are harder to find.

The unprecedented border closures and other restrictions forced people on both sides to alter long-held routines, fraying deep economic, cultural, and personal ties. Now, with the last of the restrictions lifted Oct. 1, Americans and Canadians wonder: Will things ever return to the way they were?

“I think it’s a change of habits,” said Simon Proulx, who opened La Taverne du Gamer, a quirky bar and retro video game shop on Rue Dufferin steps from the border, just before the pandemic.

In that first month, February 2020, Proulx said, about half the people who came through the door were American. Then the border slammed shut the next month to all but essential travel and stayed closed for 19 months. When it reopened, travelers faced stringent testing and vaccination rules.

Proulx said only a few American customers trickle in now.

Though many are optimistic that pre-pandemic routines will return, for now the increased separation is a cause for angst.

“It feels like you just had your arm chopped off,” said Kim Prangley, a former longtime director of the Haskell Free Library & Opera House, which sits directly on the border and attracts a mix of Canadians and Americans.

Through August of this year, 330,000 people crossed the border in passenger vehicles between Stanstead and Derby Line, Vt., according to the US Bureau of Transportation Statistics. That’s a decline of 51 percent for the same period in 2019, when there were about 680,000 crossings.

Though crossings between the two towns have risen since January, they remain stuck around 55 percent of what they were before the pandemic. The trend is similar at other border crossings from Maine to New York.

The separation has exacted a personal toll on both sides of the border.

On a recent evening, Jeanette Sisco, 64, stood in the doorway of Les Belles Affaires Stanstead, a vintage-goods store across the square from Proulx’s tavern, taking in the sunset.

Sisco has family members in the United States, including some just over the border, that she hasn’t seen in three years. During the border closure, and then with the ever-changing Canadian testing and vaccination protocols, it proved too complex.

“I don’t know if we’ll see them again,” she said.

Across the border in Derby Line, Richard Creaser, chairman of the town’s Board of Trustees, said he was unable to visit his ailing father in Canada for months. The pandemic interrupted a way of life lived on both sides of the border, he said.

A game night that he attends in Derby Line used to attract Canadians from as far north as Sherbrooke, Quebec, 50 minutes away, Creaser said. Only a handful are making the trip now, he said.

Many locals say the changes brought on by the pandemic are just the latest in a series of increasingly strict measures taken since the Sept. 11 terrorist attacks that have riven one community in two.

Years ago, Canadians would go to the United States to give birth because the hospital was closer, while the local American high school’s hockey team would play its home games at an arena in Canada. As long as people checked in at the border posts, they could cross freely back and forth along the many small streets that linked Stanstead and Derby Line.

But with 9/11 came more US Customs and Border Protection officers and barricades on the unguarded streets. Even at the Haskell Library, a symbol of unity, officials installed large flower pots to mark the border across the lawn, Creaser said.

The latest disruptions during the pandemic had consequences far beyond the little communities abutting the border. The economies of New England and Quebec, especially the Cantons de l’Est region along the border, have been deeply intertwined for more than a century. But the pandemic put stress on those links.

Steve Malenfant, 48, owns a company in Magog, Quebec, that installs and maintains high-tech industrial equipment. During the pandemic, he said, he had to lay off his American workers at the Littleton, N.H.,-based affiliate he started in 2016, because it was too hard for their Canadian supervisors to cross the border.

Malenfant, speaking in his office 18 miles from the border, said he had to turn down jobs from paper mills in Maine and New Hampshire as he restructured his business back toward Canada. He estimates he lost $1.2 million in American business. He will try to rebuild that part of the business next summer, he said.

“We’ve got the experience of having already done it, so it will go faster,” Malenfant said. “Really, we won’t restart at zero … maybe 25 percent.”

Many American businesses also lost Canadian clients during the height of the pandemic, said Pierre Harvey, a Sherbrooke-based consultant.

“The trust was lost, and the Americans found other supply chains,” Harvey said. “Now you’re running after your own tail to get back into the network and rebuild relationships.”

In the Cantons de l’Est, known for its outdoor economy built around lakes, forests, ski slopes, and sweeping views, the tourism sector is struggling with the same issues, business leaders say.

“For the tourism industry, it was truly catastrophic,” said Caroline Sage, owner of Parc de la Gorge in Coaticook, Quebec. “There are many [hotels] that survive just on that clientele.”

Sage estimated that before the pandemic, 15 percent of the visitors to the nature reserve she runs were American. Now it’s more like 4 or 5 percent, which could pose a problem for Parc de la Gorge, because it counts on American leaf peepers during the autumn season.

Despite the worries, many near the border believe the two sides will come back together. US-Canada trade rebounded in 2021 after a pandemic dip, and locals in Stanstead say they’re seeing more American license plates. Likewise, those in Derby Line are seeing more Canadian ones. And for many people, things are already back to normal.

On Canusa Street, which runs exactly along the international border between Derby Line and Stanstead, Luc Godbout, 52, was heading home from work one evening last month. He crosses the border every other day to buy cheaper gas and groceries in Vermont. “It takes two minutes,” he said with a shrug.

“We don’t really think of ourselves as two different countries for the most part,” Creaser said. “[The pandemic] certainly forced us to recognize a bit of separation that we didn’t have before. … It’s bruised a little, but I don’t think it’s broken.”