the death of his mother in 1928 eliminated his sole reason for remaining in Chicago, and when offered a promotion at the post office, he quit the next day and soon left for New York.
In New York, he became a protégé of Elliot E. Cohen, the brilliant editor of the Menorah Journal, and began to publish in the American Mercury, Dial, and other prominent literary magazines.
What distinguished Halper as a writer was his characteristic slangy, conversational style, his skill in bringing characters to life, and his uncanny ability to reproduce context and ambience.
As a result of his childhood poverty and his literary focus on workers, Halper was sometimes called a proletarian writer, a title he rejected both because it implied allegiance to the Communist Party and a lack of interest in non-proletarian segments of society.
Communists were not hard to find in Depression New York, but Halper never joined the party and in his memoir revealed his horror at the cruelty he observed at a meeting of the John Reed Club.