Background
He joined the bakers' union, which was controlled by the Bund, and owing to his superior education and fluency in several languages, was elected assistant secretary within the union by 1906. By age 15, David was a committed socialist. In 1907, David was arrested for helping to plan a bakers' strike and was held for three days. In January 1908, David was arrested again, this time for attending a union election meeting held without a police permit. Not quite 16, the boy was held for 18 months in jails in Łódź, Warsaw, and Moscow, before being sentenced to exile in Chelyabinsk, Siberia. He walked out of the camp where the authorities were holding him and, after several months hiding in Chelyabinsk and Białystok, managed to make his way to the United States in 1911 with a ticket sent to him by one of his brothers, who was living in New York City.