In her first show at Paula Cooper Gallery in Chelsea, the painter Cecily Brown showed a large triptych, “A Day! Help! Help! Another Day!” (2016). The 33-foot-wide work, which draws its title from an Emily Dickinson poem, was an energetic field of colorful marks typical of Brown’s expressionistic style.

According to her usual preference, it was placed relatively high up on the wall. But the process was redirected by Cooper herself, an art world veteran who has had her own gallery for 53 years.

“Paula walked in and said, ‘No, no, it’s got to go lower. One has to be immersed in the painting,’” Brown recalled. “She was so right. Now I hang them lower, so you can step into them.”

Cooper’s eye — and her ability to convince others that she’s right, firmly herding artists along the way — are among the reasons that Brown, after a stint at Gagosian and then a brief interval with no dealer, signed up to work with Cooper, whom she called a “female legend.”

The legend turned 83 in March, and this month Cooper is announcing four new partners in her gallery: Steve Henry, its director, tapped as senior partner; her son Lucas Cooper, a former record executive who will be a managing partner; and two longtime employees, Alexis Johnson and Anthony Allen.

At the same time, the gallery intends to turn a Palm Beach, Fla., seasonal pop-up into a year-round branch, which would be its first outside New York at a time when some galleries have many outlets. The expansion shows the influence of Henry, who has been spearheading the project.

Last month, Cooper was relaxed and candid as she talked about these decisions in a back room of her temporary gallery on West 26th Street. She has two permanent spaces on West 21st Street: her flagship, established in 1996, currently shuttered for construction, and another that has reopened after a fire.

“I’m tired, and I’ve never loved the social part,” Cooper said, while emphasizing that she is stepping back but not retiring. “I gradually stopped doing certain things.” She added that the evolution of the partnerships was “organic,” a natural development from the way she has been working with these four people for years.

Though she had a mild bout of Covid in December, which she said she mostly “slept through,” Cooper added that she’s in good health now and has received a vaccine; so has her husband, the editor and publisher Jack Macrae. (The couple opened a bookstore, 192 Books, on 10th Avenue in Chelsea, in 2003.)

Her interests are twofold from here: “Working with artists and installing.” She added, “Installing shows is my great love.” She favors letting the works have some air around them — no crowding on the walls.

Few dealers have been at it as long. Cooper opened the first gallery in SoHo in 1968, helping make it the legendary art neighborhood of the 1970s and ’80s; then she did the same thing to Chelsea in the mid-90s.

Now Cooper has chosen to make a carefully considered handoff instead of just calling it quits. The direction of her gallery, not mega-sized but large in stature, is a telling data point for the state of the art world, especially given the recent announcement by Metro Pictures, on West 24th Street, that it would close after more than 40 years.

“I’m very sorry that Metro is closing,” Cooper said. “They have been such a fine, strong, straight gallery — no fooling around. It’s the end of an era.”

Cooper has a reputation of not suffering fools. “I’m so judgmental,” she said, laughing. Her son Lucas, who joined the gallery in 2013, put it this way: “I don’t know if she’s tough.” He paused. “But I wouldn’t mess with her.”

The Metro Pictures’ closing raises questions, Cooper said, about the future of “the midsize gallery that has been able to flourish.”

From the beginning, “I didn’t want to be a big business,” she said. “The long-term strategy was to remain ‘a gentleman art dealer.’” The mega gallery was never her model. “If I wanted to be a mega-something, I would not choose art,” she said, noting that she toyed with opening a Paris branch around 1980, but decided against it because of the challenging logistics.

Cooper made her name showing, and also selling, Minimalist and Conceptual art, when those movements were just getting going; she was one of the pioneers who taught collectors that the idea for a work — like a set of Sol LeWitt’s instructions for his wall drawings, with the execution carried out by someone else — had value, not just the physical object. It revolutionized art in the 1960s and ’70s.

Her now more varied roster still has a strong Conceptual strain. Adam D. Weinberg, the director of the Whitney Museum of American Art, said that Ms. Cooper’s lineup has a “cerebral cast of mind, but not aridly so.”

It includes Christian Marclay, famed for his 24-hour-long film montage “The Clock,” as well as the estates of LeWitt, the sculptor Carl Andre and the photographers Hilla and Bernd Becher, known for their austere water tower pictures.

“I think we show tough stuff,” Cooper said. “That means people have to take time and think about it.” The show opening April 24, “No More Than Three Other Times,” features three generations of conceptual artists: Douglas Huebler, Sherrie Levine and Walid Raad.

Weinberg recalled going to her gallery in SoHo in his 1970s college days. “It was through her that I fell in love with Minimal and Conceptual work,” the director said. “It was the first time I ever saw Sol LeWitt’s work.”

As Weinberg put it, “She has curated her successors as carefully as she has curated her shows.”

Henry has been a director since 1998, after getting to know Cooper when he worked for the Los Angeles gallerist Margo Leavin, with whom Cooper shared artists. He said that the fact that he and Johnson, two of the four new partners, are Black, was “quite significant,” given that “there were, like, five Black people in the art world when I started.”

He added, “I think it’s changed remarkably since then. There’s a much more powerful presence of people of color in the art world now.”

Henry said he was happy Cooper “took a chance on a fresh young Black kid”; they bonded from the start over their appreciation of the artists Marclay and Rudolf Stingel. He has put his own stamp on the gallery by suggesting the addition of the filmmaker Ja’Tovia Gary, among others.

“The idea of the radical is in our DNA,” Henry said.

Cooper, born Paula Johnson and raised in Massachusetts, got her first New York gallery job in 1959. In 1964, she opened her own space briefly, but it was short-lived. So, too, was a first marriage. “My first husband didn’t allow me to work, so I stopped being married,” she told the Times in 2016. (She married again, to Neil Cooper, a music producer and record label founder, and they divorced in the ’80s).

From 1965 to 1967, she had a job that epitomized the loose spirit of the era, directing Park Place Gallery, a cooperative. Her bosses were 10 artists including the sculptors Robert Grosvenor and Mark di Suvero, both of whom she now shows.

“They call it ‘taste,’ di Suvero said. “But it’s responding to work, and Paula has a great capacity for that.”

The hardheaded quality needed to succeed in business was in evidence, too. Di Suvero said, “She was able to keep this crazy group of artists together, which wasn’t easy.” In particular, she found some financial backers, which helped, given that di Suvero said there were “practically no sales.”

Finally in 1968, Cooper opened the gallery that still bears her name on Prince Street (later it moved to Wooster Street). In that era, a woman dealer wasn’t a unicorn — Bertha Schaefer, Martha Jackson, Betty Parsons and Joan Washburn were active — but “people treated you so condescendingly,” she said. “A woman couldn’t be a major dealer, she was second tier.” The dealer Dick Bellamy, she recalled, “used to pat me on the head.” This, despite the fact that she was 30 with two children when she opened her doors.

And to those outside the art world, gallerist was a socially acceptable profession for a woman. “The arts were ‘clean hands,’” she said. “Ladies could concern themselves with such things.”

Cooper’s political cast of mind quickly put to rest the idea that she’d show demure art. Her initial exhibition was explicitly anti-Vietnam.

“I had friends who wouldn’t talk to me, I was so against the war,” she recalled. She also didn’t take any of the proceeds for herself, splitting them between the artists and antiwar causes. She has given first or early shows to Jennifer Bartlett, Lynda Benglis, Jonathan Borofsky, Elizabeth Murray, Joel Shapiro and Robert Gober. Other dealers have picked off her successes. Cooper lost Gober and Tony Smith’s estate to Matthew Marks; and she lost Murray and Donald Judd to Pace (which then subsequently watched them go elsewhere).

“Artists only get stolen when they’re doing well,” she said.

Cooper’s lack of interest in expanding the gallery may have been a factor in some departures, though she “never, ever” had regrets about her path.

And the losses hurt: Gober’s move left “my heart broken,” she said, noting that she “doesn’t hold it against” the artists or the other dealers. “Sometimes, they just want a different experience,” Cooper said. She added that “sometimes they come back, too.”

Rachel Uffner, a younger dealer who opened her gallery in 2008, said that she saw something significant in the fact that Cecily Brown and the multimedia maker Tauba Auerbach have joined Paula Cooper in the past decade.

“These are strong female artists who seem to have sought this relationship as a kind of refuge from the market,” said Uffner.

Arne Glimcher, Pace’s founder, also 83, is perhaps the only person with similar longevity in the art business. A famous 1970 group photo in Vogue, intended to showcase New York’s up-and-coming dealers, included him and Cooper, the only woman in the bunch.

Taking the long view, Glimcher praised Cooper’s adaptability, after having made her name with Minimal and Conceptual works. “She has been much more open to other styles in the later half of her career,” he said.

Musing on her own track record in the business, Cooper said, “I can’t think of any artists I’ve stolen.”

But she smiled when she added, “Maybe that will change.”