Jane Fonda was about to spend the night in jail.

But it wasn’t 2019, and it wasn’t for protesting U.S. policy on climate change — something Fonda has done every Friday in Washington since early October. It was the 1970s, and 32-year-old Fonda — in the throes of a professional, personal and ideological rebirth — had just been booked in a Cleveland jail on trumped-up charges of drug smuggling.

Later, an officer told her that orders for her arrest came straight from the Nixon White House. Displeased by her anti-Vietnam War activism, the FBI and CIA had been surveilling her for months. The National Security Agency was tapping her phone calls.

Fonda knew none of that on Nov. 3, 1970. But as she posed for a mug shot — her dark hair cropped close, with shaggy bangs — she raised one fist in defiance anyway.

The grainy, black-and-white image shaped a generation of women activists.

“At the time, there was this expectation that the only way a woman could be in public was to present herself in full makeup, respectably dressed, a skirt, a well-controlled girdle,” said Kirsten Swinth, a Fordham University professor who studies U.S. women’s history. The mug shot “says you can be something different than what society has told you you can be.”

It also marked the beginning of a hairdo sensation. The black-and-white photo introduced America to bad-girl bangs — and Fonda’s appearance in 1971 crime thriller “Klute,” sporting the same haircut, launched the look into the cultural stratosphere.

Women across the country — some men, too — began asking their hairdressers for variations of the “Klute cut.” It continues to inspire hairstyles on fashion runways almost 50 years later.

Fonda, who was unavailable for an interview, is well aware of the staying power of the mug shot. On her personal website, she sells sweatshirts, hoodies, T-shirts, tanks and coffee mugs emblazoned with the picture (and dedicates all proceeds to the Georgia Campaign for Adolescent Power and Potential).

As Fonda told the Los Angeles Times in 2018: “I sure got a lot of mileage out of that arrest.”

Her path to the Cleveland jail began months before the booking, when she decided to visit her then-husband Roger Vadim’s hairdresser in New York City. Her marriage to the French director and movie producer was falling apart — he drank, gambled and cheated — and she was working to rediscover herself as a person and an actress, “prob[ing] deeper into the character and into myself than I had before,” Fonda wrote in her autobiography “My Life So Far.”

Seeking radical change, she told stylist Paul McGregor: “Do something.” He did. McGregor sheared off her long, blond locks, dyed the strands “darker, like what it really was” and left a jagged, imperfect, impudent fringe.

“Hair had ruled me for many years … the men in my life liked it long and blond,” Fonda wrote. But now “I looked like me! I knew right away that I could do life differently with this hair.”

A few months after that, she ended her marriage. She agreed to play spunky call girl Bree Daniels in “Klute,” a role different from anything she’d acted before. And she began pouring herself into various activist movements, especially the protests against the Vietnam War.

Fonda started calling herself a “feminist” in public and ditched her old wardrobe. While married to Vadim, she had favored “ultrashort miniskirts, revealing blouses, and makeup … all designed to attract men’s attention,” Fonda wrote in “My Life So Far.” Now she opted for jeans, “drip-dry” T-shirts and army boots.

“The activism upon which I embarked in 1970 changed me forever in terms of how I saw the world and my place in it,” Fonda wrote. Part of that meant refusing to “look the way I was supposed to anymore.”

By rejecting a “hypersexualized image” of herself, historian Swinth said, Fonda acted out a powerful strand of feminist rebellion that was just beginning to emerge at the time.

“That’s part of the Jane Fonda story, that flip from the sex kitten image to the powerful activist woman,” Swinth said. “In that sense, it’s spot on to think of her as a model of a new feminist outlook.”

Equipped with her new hairdo, new wardrobe and newfound commitment to social justice, Fonda had just landed in Ohio after delivering an anti-Vietnam War speech in Canada when airport officials demanded — without explanation — to open and search her luggage.

Rummaging around, authorities found small, plastic vitamin bottles and concluded they must be illegal drugs. Two “hulking FBI chaps” imprisoned Fonda in a room for three hours, she wrote in “My Life So Far,” refusing to let her phone a lawyer or even rise from her chair.

After awhile, “desperate” to use the restroom, Fonda tried to push aside an agent blocking her way and was promptly arrested for assaulting an officer, as well as drug smuggling. Authorities handcuffed the actress, took her to the Cuyahoga County Jail, fingerprinted her, snapped a mug shot — then passed out of history.

“I was in a cell for ten hours … the next day I was brought from jail in handcuffs past a phalanx of TV cameras and photographers,” Fonda wrote in “My Life So Far.” “As my hands are slender and double-jointed, I easily slipped out of one handcuff and threw a ‘power to the people’ fist in the air, much to the chagrin of the guards.”

Fonda was released on bonds totaling roughly $5,500, and all charges were later dropped. The day after she appeared in court, Fonda was “back on the lecture circuit,” she wrote.

She would not spend another night behind bars until almost half a century later, when Fonda slept in a D.C. jail after police arrested her for demonstrating against climate change on Capitol Hill in early November. The 81-year-old actress was released the next day when the government declined to press charges. Undeterred, Fonda told The Washington Post she plans to keep protesting every Friday through early January.

These days, Fonda’s hair is blond again — still short, less shaggy. Police did not publish a booking photo this time around. Still, the 1970 mug shot may have a 21st-century successor.

Week after week, arrest after arrest, the winterberry-red coat Fonda wears to every protest has gained fame of its own. As the chief fashion critic of the New York Times concluded last month: the coat “has made that rare but historically significant leap from garment to symbol: of a time, place and movement.”

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