A sign at Costco reminding customers of Bergen County’s blue laws. Photograph by Najlah Feanny/Corbis

Mitch Horn heard his call to action in a Babies R Us outside Secaucus, New Jersey. For the third Sunday in a row, Horn had made the forty-minute round trip from his home in Hackensack, crossing from Bergen County to neighboring Hudson County to pick up the wants and needs of contemporary parenting—on this particular day, fresh onesies. The ordeal was maddening to him. On any other day of the week, he could drop by his local Babies R Us, less than five minutes from his front door. And in any other county in America, he could legally do so on a Sunday.

“It’s all about our liberties,” Horn told me. “We should have the right to sell goods and to buy goods on any day or at any time that we choose.” So, with the ease of Facebook, he launched a movement: Modernize Bergen County.

Just across from Manhattan, via the George Washington Bridge, is Bergen, the last county in America that still enforces the kind of broad-spectrum Sunday shutdown that was common nationwide until the nineteen-nineties. Many jurisdictions still restrict some Sunday transactions, mainly the sale of alcohol, but in Bergen, you can’t buy a new frying pan on a Sunday, or a bag of nails, or a four-pack of Gerber Neutral Sheep and Polka Dot Assorted Onesies.

This may not be surprising in a backwoods county in the Bible Belt, but Bergen can be fairly described as modernized. It is, for example, highly dependent on the consumer economy. After the Second World War, the borough of Bergenfield built one of the nation’s first pre-planned suburbs featuring shopping malls; the county is now a megapalooza of outlet malls and big-box stores for shoppers, many of them from New York. Yet, by the late nineteen-fifties, Bergenites had begun to place prohibitions on Sunday sales. At the time, such “blue laws”—historians say that the term stems from the color of paper Puritans used to print their Sunday trading laws, or else from a slang term for Puritanism in that era—were common across the United States. Today, Bergen is their last redoubt. If its blue laws fall, so does America’s last true sabbath from shopping.

To understand what makes Sunday sacred in Bergen, it’s best to start with Saturday in Paramus, a borough in the heart of the county. Paramus is divided by three major highways, each exit ramp leading to an abundance of shopping opportunities. The greatest of these, a stone’s throw from Paramus’s town hall, is the Garden State Plaza, which is the kind of mall where you can buy an eighty-thousand-dollar Tesla Model S right out of the storefront, and where your boot prints are swiftly mopped away. Garden State Plaza attracts nineteen million visitors a year, or an average of sixty thousand every shopping day. On Saturdays, its eleven thousand parking spaces fill to their farthest edges (valet parking is available). The shopping rush contributes to bumper-to-bumper traffic on Bergen County’s highways, and Paramus’s byways are frantic with rat runners—people trying to avoid the congestion of main roads.

Paul Contillo, a Paramus resident who in a forty-four-year political career held offices ranging from borough councillor to state senator, told me that when he first moved to Bergen County from Brooklyn, in 1955, Paramus was a rural borough—“deer, fox in the backyard”—and people did their shopping on Main Street in nearby towns like Hackensack. But by the end of 1957, Paramus was home to the largest shopping complex in the country.

The impact on small retailers was substantial: within three years, ten per cent of Hackensack’s Main Street businesses would close. As a survival strategy, mom-and-pop shops—afraid that they’d have to work seven days a week or pay for Sunday staff—joined with church groups and residents concerned about traffic congestion to press for blue laws. Already concerned about traffic to new discount outlets along the highways, Paramus had passed its own local law two months before the borough’s first mall even opened. Two years later, the New Jersey legislature let each county choose whether to hold a referendum on a state-level blue law that would forbid the sale of clothing, furniture, appliances, and building materials on Sundays; twelve of the state’s twenty-one counties opted in, including Bergen.

Blue laws forbidding Sunday work have been on the books in the U.S. since 1650, and in New Jersey since 1693. At their peak in the early nineteen-sixties, general Sunday-trading bans were in place in thirty-four states. Then began a steady decline. Blue laws in New York state were struck down in a 1976 court decision stating that a “gallimaufry of exceptions” had undermined the restrictions’ credibility. Factors ascribed to the end of blue laws elsewhere include the absurdity of some local rules (in the nineteen-eighties, Paramus tried to ban the operation of mainframe computers on the day of rest), rising time pressures on two-worker families, fading trade-union influence, the advance of shopping as recreation, and the neoliberal argument for what one advocate called “free trade on Sunday.”

So why, then, have blue laws endured in Bergen County? “Paramus,” Contillo said. “That’s the answer I can give you: Paramus. What about Paramus? The sheer volume of what goes on here.”

Over the years, economists have maintained a running debate over whether Sunday trading increases retail sales or simply redistributes spending across an extra day. There are real-world examples of local economies that appear to have suffered under blue laws, and others that appear to have not. But Paramus both has the toughest blue laws in the United States—its Sunday-trading restrictions exceed the statute that applies at the county level—and lies in one of the top-ten zip codes for retail sales in the country. The town also has a median household income more than twenty-five-thousand dollars higher than the figure for New Jersey. (Bergen as a whole is among the state’s wealthiest counties.) Whether the relationship is causal or coincidental, Paramus’s economic success has given residents at all tiers of society reason to preserve the status quo.

Contillo said that Bergen County’s blue laws have, over the decades, evolved into a civic institution that crosses partisan and even religious lines. “It’s a family day,” he told me—the one day of the week that most people can be sure of the company of those they care about, and when the options for activity are more social than commercial. I asked him whether this amounted to resistance to consumerism. “Well, we use a different word for it,” he replied. “We call it ‘quality of life.’ ”

If you’re old enough to remember when blue laws were common, Bergen on a Sunday is a nostalgia trip. Kids play road hockey, skateboarders practice kickflips on open swaths of pavement, and you may suddenly notice the cawing of blue jays. The locked Garden State Plaza, lost among its empty parking lots, seems vaguely apocalyptic. The scene is liberating, but also heavy with the demand that free time places on the self. You find yourself constantly checking your cell phone for messages.

“That’s a little snapshot of what it must have been like around the country,” Judith Shulevitz, author of “The Sabbath World” (2010), told me. “This was once just as commonplace as anything American.”

More than twenty-one years have passed since Bergenites voted on whether to keep their consumer sabbath. At the time, the result was unequivocal: nearly sixty-five per cent of voters backed the blue laws, pulling a majority in sixty-six of sixty-nine Bergen towns. In Paramus, blue-law supporters outnumbered opponents thirteen to one.