This article describes what it means to be a comprehensive teachers union, one that integrates industrial unionism, professional unionism, and social justice unionism, providing a historical context for this evolution. The author relates his own journey in becoming a union organizer and then in building public spaces for teachers to find their collective voice and power, first in more adversarial settings and then through labor-management collaboration in the professional setting of teaching and learning. He describes how the union becomes the vehicle for transforming teaching into a genuine profession and how this collective efficacy can be realized against a deeply entrenched top-down command-and-control system. The union cannot make this journey alone; it has to do it in partnership with school management and school boards through labor-management collaboration and a systems transformation vision and strategy. Ultimately, this is a strategy not only to democratize teaching but also to democratize learning for students.