When a character in F. Scott Fitzgerald’s “This Side of Paradise” blasts popular literature of the day, he cites “Fanny” Hurst among several authors “not producing among ’em one story or novel that will last 10 years.” Harsh, yet not far off the mark: Fannie Hurst was one of America’s highest-paid writers, but few of her tales of shopgirls, boardinghouse dwellers and immigrants are still in print. These days, when she’s not being confused with entertainer Fanny Brice, she’s mostly remembered for the multiple film versions of her short story “Humoresque” and of her bestselling novels “Back Street” and “Imitation of Life.”

In “Fannie,” the first full-fledged biography of Hurst, Brooke Kroeger concedes her subject’s literary shortcomings. But she makes a convincing case that Hurst was a literary trendsetter who used her celebrity to promote an agenda that included racial equality and women’s rights. An early supporter of African-American writer Zora Neale Hurston (who worked briefly as her secretary) and a friend of Eleanor Roosevelt’s, Hurst saw beyond the jargon of the causes she championed. She encouraged men to support equal opportunity for women, for instance, but challenged her gender to live up to the bargain, mocking the “languid psychology” of women engaged in “the industry of gold digging.”

Hurst came into prominence before World War I with a string of heartwarming yet realistic short stories that led reviewers to dub her the female O. Henry. Literary types scorned her sappy plotting and “careless” writing, though some praised her intuitive rendering of women’s emotional lives. One superb example is “Hattie Turner versus Hattie Turner,” which ran in Cosmopolitan in 1935. The title character so fervently wishes her abusive husband would die that after he is killed she has trouble convincing herself she’s not the murderer.

Short stories were Hurst’s strong suit, but then as now, book publishers preferred novels, and her novels could be excruciating reads, full of corny metaphors and clunky prose. From “Anywoman”: “The days were transmission belts under her feet, moving her along.” From “Imitation of Life”: “Delilah might be said to have risen like a vast black sun over the troubled waters of the domestic scene, laying them and the hordes of fears, large and small, that had dogged her heels all day.” (No wonder Langston Hughes was moved to pen the theatrical parody “Limitations of Life.”)