A voice of the radical working class during the Great Depression, Jack Conroy was the son of a union organizer, born and raised in the mining camps near Moberly, Mo. Conroy was weaned on Socialist thought through his father and the nickel pamphlets of the Haldeman-Julius Company, and was encouraged to pursue an interest in literature. As a boy, he wrote and edited his own four-page newspaper, printing it by hand on scraps of butcher paper and distributing it among family and neighbors, and by the time he was admitted to the University of Missouri in 1920, he was already showing a distinctively populist edge.

The University, however, was not in his future. After only one term, Conroy dropped out of school rather than take part in the compulsory military training, and went on the road, traveling the country by boxcar, taking odd jobs as a migrant worker, in auto factories, and steel mills. Barely managing to stay afloat financially, he married Elizabeth Gladys Kelly in June 1922, with whom he had three children.

Neither poverty nor the rigors of work held Conroy back from his goal of becoming a writer. In the late 1920s, he began to publish poetry and essays reflecting a working class perspective on the inequities of life in America, writing in a style he later described as "vivifying the present." Intensely political by nature, he associated broadly with a number of rebels, Communists, and working class radicals, though Conroy himself was never doctrinaire, often earning criticism from the more dogmatic for being insufficiently radical, and criticism from the right for being too radical.

In 1931, Conroy took over as editor of the , a "little magazine" associated with the International Workers of the World, and soon enjoyed his first literary success. A short story he published in attracted the attention of H. L. Mencken, who asked Conroy for a contribution for the . The result, "Hard winter," was lauded by Mencken and held up as a gripping account of what life in the Depression was really like. Mencken became one of Conroy's biggest supporters, accepting several more of Conroy's stories (yielding much-needed income), and helping him to land the contract for his first novel. Based loosely on his experiences riding the rails and working in automobile factories, (1933) sold poorly, but was a critical sensation. It has been described as the first "proletarian" novel written in the United States by a true proletarian, and since the 1960s, it has become a minor part of the cannon of Depression-era literature. His second and more polished novel, , appeared two years later to similar acclaim, but even poorer sales.

Conroy launched a second little magazine in 1933, the , transforming it in just over three years into the most successful of the radical literary magazines of the decade. The published works by young writers such as Nelson Algren, Richard Wright, Louis Zara, and Erskine Caldwell, and although much of the writing was "roughhewn and awkward," in Conroy's words, it was fueled by working class rage, "bitter and alive from the furnace of experience." The success of the , however, led to it being swallowed up in a power play by the in 1937, freezing a bitter Conroy on the outside. At Algren's suggestion, he moved to Chicago in March 1938 to join the Illinois Writers Project and launched a third little magazine, the , attempting to pick up where the lamented left off. The magazine debuted in March 1939 with a lead work by William Carlos Williams, but lasted only seven numbers before it succumbed during the war.

After the failure of the , Conroy took a position as associate editor with the . His later books include five works of juvenile fiction co-authored with his friend Arna Bontemps, and numerous works on folklore and folk humor. Conroy retired to Moberly in 1966, continuing to write well into his 80s and mentoring younger radicals. He died in Moberly on February 28, 1990.