Paule Marshall, who channeled the often marginalized experiences of women, African Americans and West Indians into lyrical, passionate and politically charged fiction, notably in her debut novel “Brown Girl, Brownstones,” died Aug. 12 at a care center in Richmond. She was 90.

Her son, Evan K. Marshall, said she had dementia that worsened in the past four months. Ms. Marshall’s death comes one week after that of Toni Morrison, the Nobel Prize-winning novelist of “Beloved” and “Song of Solomon.”

“This is a grieving season for Black literature,” Imani Perry, a Princeton University professor of African American studies, said on Twitter, amid early reports of Ms. Marshall’s death.

The daughter of Barbadian immigrants, Ms. Marshall wrote about race, gender and cultural identity, focusing on the African diaspora in the Caribbean and United States. Her protagonists were almost always women — black women — who possessed a power and self-assurance that was rarely seen in print when she began writing in the 1950s.

“Traditionally in most fiction men are the wheelers and dealers,” Ms. Marshall wrote in Essence magazine in 1979. “They are the ones in whom power is invested. I wanted to turn that around. I wanted women to be the centers of power.”

Although Ms. Marshall’s fiction was never polemical, her work examined racism, co­lo­ni­al­ism and what she described as an oppressive, far-reaching system of financial exploitation. “She could see that what was happening to black people in Brooklyn and to black people in Barbados came out of the same structure of capitalism,” her biographer, Mary Helen Washington, said by phone. “I don’t think that many black writers at that moment had such a large, transnational view of the world.”

Ms. Marshall was perhaps best known for her 1959 debut, “Brown Girl, Brownstones,” a coming-of-age story that many critics consider “the beginning of contemporary African American women’s writings,” according to “The Norton Anthology of African American Literature.”

Partly autobiographical, the novel was centered on Selina Boyce, a bookish 10-year-old in a West Indian section of Brooklyn, where she is alternately buoyed and weighed down by her family’s Barbadian heritage. Her eyes, Ms. Marshall wrote in the opening pages, “were not the eyes of a child. Something too old lurked in their centers. They were weighted, it seemed, with scenes of a long life. She might have been old once and now, miraculously, young again — but with the memory of that other life intact.”

A methodical writer who sometimes spent two weeks searching for the appropriate word, Ms. Marshall went years without publishing, only to release a new novel or story collection that reverberated among critics and fellow authors, even as it bypassed bestseller lists.

Her second novel, “The Chosen Place, the Timeless People” (1969), explored the tension between tradition and modernization on a Caribbean island, and was praised by New York Times reviewer Robert Bone as “the best novel to be written by an American black woman.”

It was followed by “Praisesong for the Widow” (1983), an American Book Award-winning story of a woman’s spiritual rebirth on Carriacou, an island in the Grenadines. Washington Post book critic Jonathan Yardley called it “a work of quiet passion” and “a work of exceptional wisdom, maturity and generosity, one in which the palpable humanity of its characters transcends any considerations of race or sex.”

Ms. Marshall drew praise from poets Dorothy Parker and Langston Hughes, who invited her on a 1965 cultural tour to Europe, as well as novelist Alice Walker, who wrote that Ms. Marshall was “unequaled in intelligence, vision, craft by anyone of her generation.”

In a statement, Pulitzer Prize-winning playwright Lynn Nottage said that Ms. Marshall, her godmother, nurtured aspiring writers and “was instrumental in giving a vibrant and authentic voice to a generation of young women of Afro-Caribbean descent, who felt invisible and marginalized upon arriving in America.”

Ms. Marshall was born Valenza Pauline Burke in Brooklyn on April 9, 1929. Her father juggled low-paying jobs and left the family when Pauline was 11, joining Father Divine’s evangelical “kingdom” in Harlem. Her mother was a housekeeper who spent her days “scrubbing floor,” as her mother and her friends put it, to earn “a few raw-mouth pennies.”

“I grew up among poets,” Ms. Marshall wrote in a 1983 essay for the Times, recalling the formative hours she spent in the kitchen, where the neighborhood mothers talked “endlessly, passionately, poetically and with impressive range.”

“For me, sitting over in the corner, being seen but not heard, which was the rule for children in those days, it wasn’t only what the women talked about — the content — but the way they put things — their style,” she added.

Ms. Marshall went on to combine the rich vernacular of her childhood kitchen with a literary sensibility, inspired by writers such as African American poet Paul Laurence Dunbar.

Not by coincidence, they effectively shared the same name, which Ms. Marshall said she changed at 13 after deciding Pauline “was a limp name.” She dropped two letters and pronounced Paule without the “e.”

Ms. Marshall was studying for a career in social work when tuberculosis forced her to drop out of Hunter College, part of the City University of New York, and spend a year at a sanatorium. Immersing herself in books and letter writing, she decided to study English upon her return, then transferred to Brooklyn College and graduated in 1952.

Her marriages to sociologist Kenneth Marshall and Haitian businessman Nourry Menard ended in divorce. In addition to her son, a London yacht designer from her first marriage, survivors include a stepdaughter and two grandchildren.

Working periodically as a journalist, Ms. Marshall was a writer and editor at Our World, a black “picture” magazine, in the mid-1950s. “After several years I became terrified that I was going to spend my life as a hack writer for a third-rate magazine,” she told the South Florida Sun-Sentinel in 2001. “In desperation I went home that night and started the first novel.”

“If it had been published in 1979, rather than 1959, she would have been Toni Morrison,” Washington, her biographer, told The Post in 1991. “She explored a black woman’s consciousness and broke out of convention. It was too early. She has always been just this side of being a famous, successful writer.”

Ms. Marshall was active in the civil rights and black nationalist movements and contributed to Freedomways, a leading African American journal, in the 1960s. She later taught English and creative writing at Virginia Commonwealth University in Richmond and New York University, and received fellowships from the Guggenheim and MacArthur foundations.

Her other books included “Soul Clap Hands and Sing” (1961), a collection of four novellas; “Daughters” (1991), about a Caribbean politician’s daughter in Manhattan; “The Fisher King” (2000), about the death of a jazz legend; and “Triangular Road” (2009), a memoir.

While some critics pigeonholed Ms. Marshall as a black female author writing strictly for black women, she noted that her themes were universal — and if her books had special importance for African Americans or West Indians, so much the better.

“Humans are always trying to overcome oppression of one kind or another,” she told the Sun-Sentinel. “The extra fillip for the black reader is to see their community given a kind of validity and even sacredness. To see your community in literature is a kind of empowerment.”