Ann Wilson, a painter who rose to prominence among the art luminaries who clustered in an industrial stretch of Lower Manhattan in the late 1950s, creating an eruption of art between the peak of Abstract Expressionism and the burst of Pop Art, died on March 11 at her home in Valatie, N.Y., in Columbia County. She was 91.

Her death was confirmed by her daughter Ara Wilson.

Ms. Wilson was the last surviving member of the influential Coenties Slip group, which also included Ellsworth Kelly, Agnes Martin and Robert Indiana. The group flourished in a bruised, brawny area near the East River in the days of decline after its industrial heyday a century before.

“During the 18th and 19th centuries, this was the heart of New York,” the New York Times art critic Holland Cotter wrote in a 1993 retrospective of the storied Coenties Slip art world. “The city’s earliest publishing houses were here, as were its theaters, and such writers as Melville, Whitman and Poe walked the streets.

“Although the neighborhood went on to become the financial district,” Mr. Cotter continued, “as recently as 30 years ago it was still making cultural history: It was home to some of America’s most distinguished and radical living artists.”

Ms. Wilson, a Pittsburgh native, landed on Coenties (pronounced coe-EN-teez) Slip in the mid-1950s. The youngest of the artists who thrived there, she drew influences from its established members, in particular Ms. Martin, a celebrated painter who blended the hues of nature with Abstract Expressionism, and Lenore Tawney, a fiber artist known for her monumental sculptural weaving.

Such earthy, elemental minimalism helped inspire Ms. Wilson’s primary medium at the time: quilts painted with abstract geometric patterns. Her best-known work, “Moby Dick,” a roughly 5-by-7-foot quilt painting from 1955, is in the Whitney Museum of American Art’s collection. She also has works in the collection of the Museum of Arts and Design in New York.

“I was interested in geometry,” she once said in an interview for the Institute of Contemporary Art at the University of Pennsylvania. “And in the colors of nature. It was just gardening, making a quilt.”

In helping to establish the folk art of quilting as a fine-art medium, Ms. Wilson “became a beacon for women artists in the avant-garde who explored alternative mediums and avenues of the arts as they were forming in a momentous time, from the 1950s to 1970s, when New York was burgeoning with new ideas and means of expression that were far outside the mainstream,” William Niederkorn, an artist and writer who mounted “1 Saint in 3 Acts,” a 2018 retrospective of her work at the Emily Harvey Foundation in Manhattan, wrote in an email.

Ann Marie Ubinger was born on Oct. 14, 1931, in Pittsburgh, the only child of John and Helen (Foley) Ubinger. Her father, who worked in public relations for a steel company, was an intellectual omnivore and a voracious reader, as was her mother, who worked as a librarian but was also a skilled painter and had studied with the renowned artist Samuel Rosenberg at the Carnegie Institute of Technology (now part of Carnegie Mellon University) in Pittsburgh.

Fascinated by art from an early age, she eventually enrolled at Carnegie Tech, where her fellow Pittsburgh native Andy Warhol was also a student. She ultimately graduated from the Tyler School of Art at Temple University in Philadelphia.

After college, she spent two years teaching art history at West Virginia University, where she read copies of ARTnews in the library and realized “there was something more brewing than I had been educated for,” she said in an interview with the art historian Jonathan Katz for the Archives of American Art at the Smithsonian Institution.

Those art ambitions led her to New York, where she fell in with her future art compatriots when they were running a paid workshop for hobbyists called the Coenties Slip Drawing School. Among the teachers were Jack Youngerman, who would become known for his exuberantly colorful abstract paintings, and Robert Indiana, who would find fame as the Pop artist who created the famous “love” image, consisting of the letters L-O-V-E stacked in a box.

Before long, Mr. Indiana suggested that she take an open loft in an old factory building at 3-5 Coenties Slip, in the shadow of the Brooklyn Bridge. The loft, which rented for $40 a month, had no electricity — power was wired in from a light fixture in the hall — and was heated with a potbelly stove.

“Not only were these artists drawn together through their ideas and their appreciation of the Slip area, but also through a continuous struggle to live there,” Art in America observed in a 2017 history of the scene. “Most of the lofts did not have hot water, heat or kitchens, and it was the Seamen’s Institute, then located on the Slip, that provided a much-needed cafeteria and warm showers.”

What the buildings lacked in creature comforts, they made up for in artistic significance. Mr. Kelly, a painter renowned for his bold, colorful abstract work, and Ms. Martin lived in the same building as Ms. Wilson. Barnett Newman, Jasper Johns and Robert Rauschenberg lived nearby, on Pearl and Front Streets.

Soon after Ms. Wilson moved in, her art life “just mushroomed,” she told Mr. Katz. “I knew everybody in town in about five minutes.”

The scene began to splinter in the 1960s as the area faced the onslaught of urban renewal, and Ms. Wilson moved a few subway stops north, to a loft on Canal Street. She became enmeshed in the world of performance art, including the so-called Happenings, which combined dance, theater, poetry and visual art. She also collaborated on installations with the artist Paul Thek.

Ms. Wilson also became close with Robert Wilson (no relation), the groundbreaking experimental theater director and playwright. She worked with him into the mid- 1970s, performing and contributing visual art to “Deafman Glance” and other works of his.

In addition to her daughter Ara, Ms. Wilson is survived by another daughter, Katherine Wilson, and a son, Andrew, from her marriage to the writer William S. Wilson. She and Mr. Wilson separated in 1966, though they never divorced. Mr. Wilson died in 2016.

As the New York art world began to move in new directions in the 1980s and ’90s, Ms. Wilson moved upstate, where she explored new mediums like Eastern European icon paintings and taught art at Dutchess Community College.

Even so, she continued to paint, an obsession since early childhood. As her daughter noted, “She always said she had to repeat first grade because all she wanted to do was draw.”