In order to avoid the military draft, Halpern emigrated to New York City in 1908 where he became associated with a group of Yiddish poets called Di Yunge (The Young Ones). He published his first book of poetry in 1919, In nyu york (In New York). That same year he married Rayzele Barron. His son, now called Isaac Halpern, was born in 1923. His second book, Di goldene pave (The Golden Peacock), was published in 1924. Halpern also wrote for satirical magazines and Frayhayt (Freedom), a communist Yiddish newspaper. He died of a heart attack in New York in 1932.
Halpern's importance can be measured in the 50 poems and 400 articles written from 1932 to 1954 on him by his contemporaries, some of whom include Jacob Glatstein, Itzik Manger, and Mani Leib.