Abern also briefly was part of a three-person Secretariat running the Young Workers League in the summer and fall of 1924 before being replaced as National Secretary on October 15 by John Williamson. In 1925 Cannon became the National Secretary of International Labor Defense, the legal defense arm of the American Communist movement, Abern joined him as assistant national secretary and thereafter dedicated most of his effort in an attempt to build the size and influence of that parallel mass organization of the Workers (Communist) Party.