Hartigan was a brash, self-taught artist who began painting in the late 1940s when the Abstract Expressionist movement, led by Jackson Pollock and Willem de Kooning, was reaching its height. From her first solo exhibition in 1951, she was considered an important artist, and her work sold briskly throughout the decade.
The Museum of Modern Art bought one of her paintings in 1953, and she was regularly featured in major exhibitions. In 1957, Life magazine called her "the most celebrated of the young American women painters."
Her paintings were alive with movement, rhythm and vivid splashes of color. A 1960 Time magazine article said "her strokes seem committed out of rage; the effect is one of extraordinary power."
By then, she had left New York for Baltimore and had begun a long descent into critical neglect. She had also begun to include recognizable figures in her paintings, which was seen as a betrayal of Abstract Expressionist principles.
Inspired by what she called the "vulgar and vital in modern American life," Hartigan introduced elements from pop culture and classic art into her paintings. Somewhat to her chagrin, she became known as a founder of pop art, a 1960s movement led by Andy Warhol that emphasized detachment and irony.
"Pop Art is not painting because painting must have content and emotion," Hartigan once said.
Still, she enjoyed the recognition: "I'd much rather be a pioneer of a movement that I hate than the second generation of a movement that I love."
Grace Hartigan was born March 28, 1922, in Newark, N.J., and grew up in rural Millburn, N.J. She taught herself to draw as a child but had little formal training in art. She married at 19 and worked as a draftsman for a factory during World War II. When she saw the work of Henri Matisse in a book, she decided to become an artist.
She settled in New York in 1945 and became part of the inner circle of three of the era's major artists -- Pollock, De Kooning and Mark Rothko.
Hartigan was a regular at the Cedar Tavern in Greenwich Village and had a two-year affair with painter Franz Kline. She became a close friend of poet Frank O'Hara, who wrote several poems about her, including the words used as his epitaph: "Grace / to be born and live as variously as possible."
For several years, she signed her early paintings "George Hartigan," as a tribute to 19th century female novelists George Eliot and George Sand, and her reputation exceeded those of such renowned female painters as Helen Frankenthaler, Joan Mitchell and Lee Krasner. She was championed by the kingmaking critic Clement Greenberg.
As Hartigan became more immersed in art history in the 1950s, she began to draw on images from traditional painting and ordinary street scenes.
One of her best-known works, "Summer Street" (1956) at the Corcoran Gallery of Art in Washington, D.C., includes a clearly recognizable fruit stand amid a dynamic swirl of patterns and colors.
In the tempestuous art world of the time, the use of figurative objects was deemed a form of apostasy. Greenberg, who considered representational art little more than kitsch, insulted Hartigan to her face and never wrote about her work again.
When she moved to Baltimore in 1960 with her fourth husband, Winston Price, a medical researcher at Johns Hopkins University, her standing in the art world "sank from view faster than the Titanic," the New York Times once reported.
She began teaching at the Maryland Institute College of Art in 1964 and became director of the graduate school of painting a year later. She held the position until her death, building the program into one of the most prestigious in the country.
In 1969, Hartigan's husband injected himself with an experimental vaccine and developed spinal meningitis. As his physical and mental health deteriorated before his death in 1981, Hartigan's heavy drinking grew worse, and she attempted suicide.
She took her last drink in 1983 and renewed her dedication to art and teaching.
Painting nearly every day at her studio in a converted department store in Baltimore, Hartigan explored printmaking, watercolor painting and new techniques, including Pointillist works. She painted portraits and other works inspired by Hollywood stars, classical mythology, Asian motifs and 18th century design.
She had regular exhibitions at galleries and museums, and an artist seemingly lost to time belatedly reclaimed a measure of glory.
"Somehow," she said, "in painting I try to make some logic out of the world that has been given to me in chaos."
Her first three marriages, to Robert Jachens, artist Harry Jackson and gallery owner Robert Keene, ended in either divorce or annulment. A son from her first marriage, Jeffrey Jachens, died in 2006.
Survivors include a sister, a brother and three grandchildren.
Legions of students and other followers were captivated by Hartigan's formidable presence and by her bold pronouncements, which were often about her place in the art world.
"I didn't choose painting," she said in 1993. "It chose me. I didn't have any talent. I just had genius."
Schudel writes for the Washington Post, where this obituary first appeared.